Question: What minor branch is sometimes attributed to the tradition in which invocation of buddhas and bodhisattvas is found?

full_context: Document 1: Buddhism: The concept of liberation (nirvāṇa)—the goal of the Buddhist path—is closely related to overcoming ignorance (avidyā), a fundamental misunderstanding or mis-perception of the nature of reality. In awakening to the true nature of the self and all phenomena one develops dispassion for the objects of clinging, and is liberated from suffering (dukkha) and the cycle of incessant rebirths (saṃsāra). To this end, the Buddha recommended viewing things as characterized by the three marks of existence.
Document 2: Buddhism: In addition, Mahayana Buddhists believe there are innumerable other Buddhas in other universes. A Theravada commentary says that Buddhas arise one at a time in this world element, and not at all in others. The understandings of this matter reflect widely differing interpretations of basic terms, such as "world realm", between the various schools of Buddhism.
Document 3: Buddhism: Two major extant branches of Buddhism are generally recognized by scholars: Theravada ("The School of the Elders") and Mahayana ("The Great Vehicle"). Vajrayana, a body of teachings attributed to Indian siddhas, may be viewed as a third branch or merely a part of Mahayana. Theravada has a widespread following in Sri Lanka and Southeast Asia. Mahayana which includes the traditions of Pure Land, Zen, Nichiren Buddhism, Shingon, and Tiantai (Tendai) is found throughout East Asia. Tibetan Buddhism, which preserves the Vajrayana teachings of eighth century India, is practiced in regions surrounding the Himalayas, Mongolia and Kalmykia. Buddhists number between an estimated 488 million[web 1] and 535 million, making it one of the world's major religions.
Document 4: Buddhism: Though based upon Mahayana, Tibeto-Mongolian Buddhism is one of the schools that practice Vajrayana or "Diamond Vehicle" (also referred to as Mantrayāna, Tantrayāna, Tantric Buddhism, or esoteric Buddhism). It accepts all the basic concepts of Mahāyāna, but also includes a vast array of spiritual and physical techniques designed to enhance Buddhist practice. Tantric Buddhism is largely concerned with ritual and meditative practices. One component of the Vajrayāna is harnessing psycho-physical energy through ritual, visualization, physical exercises, and meditation as a means of developing the mind. Using these techniques, it is claimed that a practitioner can achieve Buddhahood in one lifetime, or even as little as three years. In the Tibetan tradition, these practices can include sexual yoga, though only for some very advanced practitioners.
Document 5: Buddhism: During the period of Late Mahayana Buddhism, four major types of thought developed: Madhyamaka, Yogacara, Tathagatagarbha, and Buddhist Logic as the last and most recent. In India, the two main philosophical schools of the Mahayana were the Madhyamaka and the later Yogacara. According to Dan Lusthaus, Madhyamaka and Yogacara have a great deal in common, and the commonality stems from early Buddhism. There were no great Indian teachers associated with tathagatagarbha thought.
Document 6: Buddhism: Buddhist scholars have produced a number of intellectual theories, philosophies and world view concepts (see, for example, Abhidharma, Buddhist philosophy and Reality in Buddhism). Some schools of Buddhism discourage doctrinal study, and some regard it as essential practice.
Document 7: Buddhism: Buddhist schools vary on the exact nature of the path to liberation, the importance and canonicity of various teachings and scriptures, and especially their respective practices. Buddhism denies a creator deity and posits that mundane deities such as Mahabrahma are misperceived to be a creator. The foundations of Buddhist tradition and practice are the Three Jewels: the Buddha, the Dharma (the teachings), and the Sangha (the community). Taking "refuge in the triple gem" has traditionally been a declaration and commitment to being on the Buddhist path, and in general distinguishes a Buddhist from a non-Buddhist. Other practices are Ten Meritorious Deeds including, giving charity to reduce the greediness; following ethical precepts; renouncing conventional living and becoming a monastic; the development of mindfulness and practice of meditation; cultivation of higher wisdom and discernment; study of scriptures; devotional practices; ceremonies; and in the Mahayana tradition, invocation of buddhas and bodhisattvas.
Document 8: Buddhism: Formal membership varies between communities, but basic lay adherence is often defined in terms of a traditional formula in which the practitioner takes refuge in The Three Jewels: the Buddha, the Dharma (the teachings of the Buddha), and the Sangha (the Buddhist community). At the present time, the teachings of all three branches of Buddhism have spread throughout the world, and Buddhist texts are increasingly translated into local languages. While in the West Buddhism is often seen as exotic and progressive, in the East it is regarded as familiar and traditional. Buddhists in Asia are frequently well organized and well funded. In countries such as Cambodia and Bhutan, it is recognized as the state religion and receives government support. Modern influences increasingly lead to new forms of Buddhism that significantly depart from traditional beliefs and practices.
Document 9: Buddhism: Approximately six hundred Mahayana sutras have survived in Sanskrit or in Chinese or Tibetan translations. In addition, East Asian Buddhism recognizes some sutras regarded by scholars as of Chinese rather than Indian origin.
Document 10: Buddhism by country: China is the country with the largest population of Buddhists, approximately 244 million or 18.2% of its total population. They are mostly followers of Chinese schools of Mahayana, making this the largest body of Buddhist traditions. Mahayana, also practiced in broader East Asia, is followed by over half of world Buddhists.
Document 11: Buddhism: China is the country with the largest population of Buddhists, approximately 244 million or 18.2% of its total population.[web 1] They are mostly followers of Chinese schools of Mahayana, making this the largest body of Buddhist traditions. Mahayana, also practiced in broader East Asia, is followed by over half of world Buddhists.[web 1]
Document 12: Buddhism: Traditionally, the first step in most Buddhist schools requires taking refuge in the Three Jewels (Sanskrit: tri-ratna, Pāli: ti-ratana)[web 19] as the foundation of one's religious practice. The practice of taking refuge on behalf of young or even unborn children is mentioned in the Majjhima Nikaya, recognized by most scholars as an early text (cf. Infant baptism). Tibetan Buddhism sometimes adds a fourth refuge, in the lama. In Mahayana, the person who chooses the bodhisattva path makes a vow or pledge, considered the ultimate expression of compassion. In Mahayana, too, the Three Jewels are perceived as possessed of an eternal and unchanging essence and as having an irreversible effect: "The Three Jewels have the quality of excellence. Just as real jewels never change their faculty and goodness, whether praised or reviled, so are the Three Jewels (Refuges), because they have an eternal and immutable essence. These Three Jewels bring a fruition that is changeless, for once one has reached Buddhahood, there is no possibility of falling back to suffering.
Document 13: Buddhism: Buddhism /ˈbudɪzəm/ is a nontheistic religion[note 1] or philosophy (Sanskrit: धर्म dharma; Pali: धम्म dhamma) that encompasses a variety of traditions, beliefs and spiritual practices largely based on teachings attributed to Gautama Buddha, commonly known as the Buddha ("the awakened one"). According to Buddhist tradition, the Buddha lived and taught in the eastern part of the Indian subcontinent, present-day Nepal sometime between the 6th and 4th centuries BCE.[note 1] He is recognized by Buddhists as an awakened or enlightened teacher who shared his insights to help sentient beings end their suffering through the elimination of ignorance and craving. Buddhists believe that this is accomplished through the direct understanding and perception of dependent origination and the Four Noble Truths.
Document 14: Buddhism: According to a demographic analysis reported by Peter Harvey (2013): Mahayana has 360 million adherents; Theravada has 150 million adherents; and Vajrayana has 18,2 million adherents. Seven million additional Buddhists are found outside of Asia.
Document 15: Buddhism: According to the scriptures, Gautama Buddha presented himself as a model. The Dharma offers a refuge by providing guidelines for the alleviation of suffering and the attainment of Nirvana. The Sangha is considered to provide a refuge by preserving the authentic teachings of the Buddha and providing further examples that the truth of the Buddha's teachings is attainable.
ground_truth: Vajrayana
sub_queries: Invocation of buddhas and bodhisattvas is in what tradition? Answer: Mahayana
What minor branch is sometimes attributed to Mahayana ? Answer: Vajrayana