Question: What is the name of the unofficial grouping of elite universities that are part of the C9 Leaugue?

full_context: Document 1: Famous four universities in republican China: The Famous four universities in republican China () were four universities that moved inland to avoid the war damages while still managing to keep the schools running during Second Sino-Japanese War, namely the National Central University, the Wuhan University, the Zhejiang University, and the National Southwestern Associated University. After the war, University of Oxford acknowledged their effort and excellence by granting their students the status of seniors when they meet certain standards.
Document 2: Ivy League: The Ivy League is a collegiate athletic conference comprising sports teams from eight private institutions of higher education in the Northeastern United States. The conference name is also commonly used to refer to those eight schools as a group beyond the sports context. The eight institutions are Brown University, Columbia University, Cornell University, Dartmouth College, Harvard University, the University of Pennsylvania, Princeton University, and Yale University. The term "Ivy League" has connotations of academic excellence, selectivity in admissions, and social elitism.
Document 3: C9 League: The C9 League is an official alliance of nine elite and prestigious universities in mainland China, initiated by the Chinese Central Government through Project 985 to promote the development and reputation of Chinese higher education system by founding world-class universities in the 21st century. It is analogous to the Ivy League in the United States, the U15 in Canada, the Golden Triangle in the UK, and the Go8 in Australia. The members of the C9 League are Tsinghua University, Peking University, Zhejiang University, Nanjing University, Fudan University, Shanghai Jiao Tong University, Xi'an Jiaotong University, University of Science and Technology of China and Harbin Institute of Technology. Together they account for 3% of the country's researchers but receive 10% of national research expenditures. They produce 20% of the nation's academic publications and 30% of total citations.
Document 4: University of Cambridge: The University of Cambridge (informally Cambridge University) is a collegiate public research university in Cambridge, England. Founded in 1209 and granted a royal charter by King Henry III in 1231, Cambridge is the second-oldest university in the English-speaking world and the world's fourth-oldest surviving university. The university grew out of an association of scholars who left the University of Oxford after a dispute with the townspeople. The two medieval universities share many common features and are often referred to jointly as "Oxbridge".
Document 5: Zhongnan University of Economics and Law: Zhongnan University of Economics and Law (); abbreviation ZUEL; colloquially known by the Chinese as zhōng nán cái dà ) is a national key university located in Wuhan, China. It is one of the top 10 specialist finance, economic and juristic universities under direct administration of the Ministry of Education of the People's Republic of China. It is designated as one of the 211 Project institutions and listed in the 985 Innovative Platforms for Key Disciplines Project by the Ministry of Education of the People's Republic of China.
Document 6: University of Oxford: The University of Oxford (informally Oxford University or simply Oxford) is a collegiate research university located in Oxford, England. It has no known date of foundation, but there is evidence of teaching as far back as 1096, making it the oldest university in the English-speaking world and the world's second-oldest university in continuous operation. It grew rapidly from 1167 when Henry II banned English students from attending the University of Paris. After disputes between students and Oxford townsfolk in 1209, some academics fled north-east to Cambridge where they established what became the University of Cambridge. The two "ancient universities" are frequently jointly referred to as "Oxbridge".
Document 7: Harvard University: Harvard University is a private Ivy League research university in Cambridge, Massachusetts, established in 1636, whose history, influence, and wealth have made it one of the world's most prestigious universities.
Document 8: Oxbridge: Oxbridge is a "portmanteau" (composite word) of "Oxford" and "Cambridge", both elite universities in the United Kingdom. The term is used to refer to them collectively, both in contrast to other British universities and more broadly to describe characteristics reminiscent of University of Oxford and University of Cambridge, often with implications of superior social or intellectual status.
Document 9: University: A university (Latin: "universitas" , "a whole") is an institution of higher (or tertiary) education and research which awards academic degrees in various academic disciplines. Universities typically provide undergraduate education and postgraduate education.
Document 10: Commonwealth System of Higher Education: The Commonwealth System of Higher Education is a statutory designation by the Commonwealth of Pennsylvania that confers "state-related" status on four universities located within the state. The designation establishes the schools as an "instrumentality of the commonwealth" and provides each university with annual, non-preferred financial appropriations in exchange offering tuition discounts to students that are residents of Pennsylvania and a minority state-representation on each school's board of trustees. Legally, however, the universities remain separate and private entities, operating under their own charters, governed by independent boards of trustees, and with its assets under their own ownership and control thereby retaining much of the freedom and individuality of private institutions, both administratively and academically. It is the only public-private hybrid system of higher education in the United States that is so construed, although Cornell University, the University of Delaware, and Rutgers University represent alternative types of public-private university hybrids.
Document 11: Golden Triangle (Cheshire): The Golden Triangle is an area of affluent, towns and villages in Cheshire such as Wilmslow, Mottram St. Andrew and Alderley Edge. The exact three points of the triangle are the subject of local debate, but are generally considered to be Wilmslow, Alderley Edge and Prestbury. The area is noted for expensive houses, pleasant countryside, famous footballers, celebrities and entrepreneurs.
Document 12: Golden triangle (universities): The "golden triangle" is an unofficial grouping of elite universities located in the English cities of Cambridge, London and Oxford, as listed below:
Document 13: Oxford-Cambridge Arc: The Oxford-Cambridge Arc is a notional arc of agricultural and urban land at about 75km (about 50 miles) radius of London, southern England. It runs between the two English university towns of Oxford and Cambridge via Milton Keynes and other important settlements in Cambridgeshire, Bedfordshire, Buckinghamshire and Oxfordshire, at the northern rim of the London commuter belt. It is significant only in economic geography, with little physical geography in common.
Document 14: N8 Research Partnership: The N8 Research Partnership is a partnership created in 2007 of the eight research-intensive universities in Northern England - Durham, Lancaster, Leeds, Liverpool, Manchester, Newcastle, Sheffield and York. The N8 Research Partnership aims to maximise the impact of this research base by identifying and co-ordinating powerful research teams and collaborations across the North of England. Collectively, the N8 universities undertake more than £650 million of research income per annum and employ over 18,000 academic staff, thus forming the largest research-pooling partnership ever undertaken in the UK. The N8 Research Partnership also works closely with industry.
Document 15: China University of Mining and Technology: China University of Mining and Technology (CUMT; ), colloquially 矿大, is a national key university under the direct supervision of the Ministry of Education of China, and a Project 211 and Project 985 platform (in terms of mining) university of China. The university is ranked as the best mining university in China and has a worldwide reputation in coal mining technology and research. It has two parts: the main campus located in Xuzhou, Jiangsu Province which is called China University of Mining and Technology (CUMT), and a second campus located in Beijing (China University of Mining and Technology, Beijing, CUMTB). The latter used to be the Graduate School of CUMT. CUMT is a leading multi-disciplinary polytechnic university with mining features.
ground_truth: The "golden triangle"