Question: Who is the spouse of the singer of Eimai?

full_context: Document 1: Gia Sena: Gia Sena (Greek: "Για Σένα"; English: "For You"; also known as "Gia Sena Sakis Rouvas") is the third studio album by Greek musician Sakis Rouvas, released in October 1993 in Greece and Cyprus by PolyGram Records Greece.
Document 2: Apla Ta Pragmata: Apla Ta Pragmata () is an album by popular Greek artist Katy Garbi, released on December 14, 2001 by Sony Music Greece. The album went 2x Platinum in Greece selling over 100,000 units, and 2x Platinum in Cyprus, also producing the Platinum CD Single Ti Theloune Ta Matia Sou. Dewar's whiskey was a main sponsor of the album, including sponsorship of the album's platinum certification party.
Document 3: Zise Ti Zoi: "Zise Ti Zoi" is a single by popular Greek singer Sakis Rouvas from the "Alter Ego" original soundtrack, released on 28 May 2007 in Greece and Cyprus by Minos EMI.
Document 4: Eimai: Eimai is the name of a Greek album by singer Anna Vissi released in Greece and Cyprus in 1990 by CBS Greece.
Document 5: Noima: Noima (Greek: "Νόημα"; ) is the title of the seventh studio album by the popular Greek artist Peggy Zina, released in 2005 by Minos EMI. The entire album was written, composed and produced by Giorgos Theofanous.
Document 6: Cyprus: Popular music in Cyprus is generally influenced by the Greek Laïka scene; artists who play in this genre include international platinum star Anna Vissi, Evridiki, and Sarbel. Hip Hop, R&B and reggae have been supported by the emergence of Cypriot rap and the urban music scene at Ayia Napa. Cypriot rock music and Éntekhno rock is often associated with artists such as Michalis Hatzigiannis and Alkinoos Ioannidis. Metal also has a small following in Cyprus represented by bands such as Armageddon (rev.16:16), Blynd, Winter's Verge and Quadraphonic.
Document 7: Kravgi: Kravgi (Greek: "Κραυγή"; English: "Scream") is a studio album released by singer Anna Vissi in November 2000 in Greece and Cyprus by Sony Music Greece. The double-album was certified 7× Platinum in Greece and Cyprus, while it was also the best-selling album of the year 2000 in Greece. The album was also later released by Sony Music in Turkey in 2001 where it was certified Gold as well as in Australia and New Zealand in 2002. Today the album stands as one of the most successful albums of all time in Greece with sales of over 175,000 copies (350,000 discs). This album, along with English-language album "Everything I Am" released the same year, showcased a significant change over Vissi's stylistic and musical selections, expanding her image as a pop icon and contemporary artist as promoted in the mid-1990s and onwards.
Document 8: Autostop/Love Is a Lonely Weekend: "Autostop/Love Is a Lonely Weekend" is a limited edition single by Greek singer-songwriter Anna Vissi released in May 2006 by her former label Minos EMI.
Document 9: Emeis: Emeis (; ) is the name of a Greek album by singers Anna Vissi and Nikos Karvelas. It was released in Greece and Cyprus in 1992 by Sony Music Greece. The album has achieved gold status. It features her Vissi's song "Den Thelo Na Kseris".
Document 10: Roza Eskenazi: It was only in the late 1960s that there was some renewed interest in her earlier work. RCA recorded two 45s containing four of her songs (including "Sabah Amanes") with violinist Dimitris Manisalis, but the release was limited. All this changed, however, in the final days of the military dictatorship in the early 1970. Suddenly, the youth of the country developed a renewed interest in the urban songs of the past, and several important compilations were released. One of the best known was Rebetiki Istoria, a six-record collection of Rebetiko music, which sold hundreds of thousands of copies.
Document 11: Amin (song): "Amin" (Greek: Αμήν; ) is a rare single released by Greek pop singer Anna Vissi in 1995. The single featured "Amin" which later appeared on the repackaged edition of her popular album "Re!", as well as the track "Eleni", which Anna Vissi dedicated to her fan Eleni Karkanta. Music and lyrics for both tracks are by Nikos Karvelas.
Document 12: To Tzitziki Kai I Parea Tou: To Tzitziki Kai I Parea Tou (The Cricket And His Friends) is the name of a soundtrack to a Greek children's musical of the same name which featured singer Anna Vissi on one song. It was released in 1980 in Greece and Cyprus by EMI Columbia Greece. Music is by Sakis Tsilikis and lyrics by Giannis Kalamitsis. In 2006, the original LP was released for the first time on CD, in remastered sound.
Document 13: Kati Simveni: Kati Simveni (; ) is the name of a Greek album by singer Anna Vissi. The album was released in Greece and Cyprus by CBS Greece in 1985. This album includes her signature song "Dodeka". The album reached gold status.
Document 14: IANOS: IANOS SA is a Greek-based book, music and art retailer with several stores in the two major cities, Thessaloniki and Athens. It was named after the ancient Roman god Janus, as a link to the identity and mission of the company. IANOS sells through its concept-store chain a large variety of books, cds, art objects, periodicals, gifts and stationery. Also, it offers event venues, seminars, art galleries, a publishing house, an art café, it operates web sales (for online shopping) and runs an internet radio.
Document 15: Greece: Greece participated in the Eurovision Song Contest 35 times after its debut at the 1974 Contest. In 2005, Greece won with the song "My Number One", performed by Greek-Swedish singer Elena Paparizou. The song received 230 points with 10 sets of 12 points from Belgium, Bulgaria, Hungary, the United Kingdom, Turkey, Albania, Cyprus, Serbia & Montenegro, Sweden and Germany and also became a smash hit in different countries and especially in Greece. The 51st Eurovision Song Contest was held in Athens at the Olympic Indoor Hall of the Athens Olympic Sports Complex in Maroussi, with hosted by Maria Menounos and Sakis Rouvas.
ground_truth: Nikos Karvelas
sub_queries: Who sang or played Eimai? Answer: Anna Vissi
Anna Vissi >> spouse Answer: Nikos Karvelas