Answer the question at the end by quoting:

Rouvas was born on 5 January 1972 in the village of Mandoukion, near Corfu City on the island of Corfu, the eldest of four sons of Konstantinos "Kostas" Rouvas (an ambulance driver) and the teenaged Anna-Maria Panaretou (a duty-free shop clerk at the local airport). He has three brothers: Billy (b. Vasilios), Tolis (b. Apostolos, 1975) and Nikos (b. Nikolaos, 1991). The family was poor, and Rouvas began taking care of his brothers at age five. At age four, he exhibited athletic ability and took ballet classes as a child.
After moving to Patras, Rouvas continued to look for performance opportunities until he met Dakis (a popular Greek artist who was the first person to help him professionally). Rouvas moved to Athens, and made his first professional appearance in 1991 at the Show Centre. His showmanship attracted the attention of music executives such as Nikos Mouratidis, who encouraged songwriter Giorgos Pavrianos to produce him. Rouvas, singing Michael Jackson's "Man in the Mirror" was discovered by PolyGram executives who signed him to his first recording contract. After moving to Athens he lived with an older English woman named Sally, with whom he had begun a relationship on Corfu. Their relationship ended when Psinakis became Rouvas' manager, and the singer became more career-oriented. The media has speculated about Rouvas' personal life and relationships with model Zeta Logotheti, Sofi Kantarou (a Corfu bar manager) and singer Elli Kokkinou. Several months later he debuted at the Thessaloniki Song Festival, losing Best Vocal Performance to Giorgos Alkaios but singing the Best Composition ("Par'ta"; "Take Them", with music by Nikos Terzis and lyrics by Giorgos Pavrianos). There was a brief earthquake during the festival. Rouvas released his eponymous debut album, which topped the Greek Albums Chart, the day after the festival. "Par'ta" became a radio hit, and other songs of the album such as "1992", "Ego S'agapo" ("I Love You") and "Gia Fantasou" ("Imagine") also became popular. In September 1992 Rouvas released his second album, Min Andistekese (Don't Resist), also composed by Nikos Terzis. It produced the singles "Gyrna" ("Return"), "Min Andistekese", "Na Ziseis Moro Mou" ("Live, My Baby") and "Me Kommeni Tin Anasa" ("Breathless"), with a music video of the title track. The album's success helped establish Rouvas at the top of the Greek music scene. In October 1993 Rouvas released his third album, Gia Sena (For You), with music by Alexis Papadimitriou and lyrics by Eleni Giannatsoulia and Evi Droutsa. The single "Kane Me" ("Make Me") became a radio hit, with "To Xero Eisai Moni" ("I Know You Are Alone") and "Xehase To" ("Forget It") also receiving airplay.

What did Sakis do in his early commercial success?

made his first professional appearance in 1991 at the Show Centre.

Answer the question at the end by quoting:

Christina Maria Aguilera (born December 18, 1980) is an American singer, songwriter, actress, reality show personality and television personality. Born in Staten Island, New York and raised in Rochester and Wexford, Pennsylvania, she appeared on the television series Star Search and The Mickey Mouse Club in her early years. After recording "Reflection", the theme for Disney's 1998 film Mulan, Aguilera signed with RCA Records. She rose to prominence with her 1999 self-titled debut album that spawned the US Billboard Hot 100 number-one singles "Genie in a Bottle", "What a Girl Wants", and "Come On Over Baby
Aguilera's seventh studio album Lotus was released in November 2012. She described it as a "rebirth" of herself after the personal struggles she had overcome during the Bionic album era. The album has become her least commercially successful album so far. It peaked at number seven on the Billboard 200 and has sold 290,000 copies in the United States. The album was preceded by two singles, "Your Body" and "Just a Fool". During the promotion of Lotus in December 2012, Aguilera was temporarily replaced by Shakira for the fourth season of The Voice and returned for the fifth season in September 2013. While Aguilera's seventh studio album Lotus was commercially unsuccessful, she subsequently found her revitalized success through collaborations with other artists. She was featured on Pitbull's single "Feel This Moment" in January 2013, which peaked at number eight on the Billboard Hot 100 and was certified double platinum by the RIAA. She subsequently appeared on Mexican singer Alejandro Fernandez's cover of "Hoy Tengo Ganas de Ti", which earned a diamond certification in Mexico. Aguilera's duet of "Say Something" with A Great Big World, released in November 2013, was met with critical acclaim and commercial success, earning a six-time platinum certification from the RIAA and winning a Grammy Award for Best Pop Duo/Group Performance. Aguilera became engaged to Rutler in February 2014. She gave birth to their daughter, Summer Rain Rutler, in August 2014. For the sixth and seventh seasons of The Voice, Aguilera was respectively replaced by Shakira and Gwen Stefani, clarifying that she wanted to devote her time to her family. She subsequently returned as a coach for the eighth and tenth seasons; for the latter she won with her contestant Alisan Porter and became the first female coach to win the show. In April 2015, Aguilera played a recurring role as singer Jade St. John on the third season of ABC's musical drama series Nashville. In March 2016, Aguilera and Rutler were announced as executive producers for a new music-based game show, Tracks, to air on Spike TV. Aguilera recorded a song titled "Change", which was dedicated to the victims of the 2016 Orlando nightclub shooting as well as Christina Grimmie, who was fatally shot in Orlando the day before the nightclub shooting, in June 2016. The proceedings were donated to the National Compassion Fund to benefit the victims' families. She further recorded a disco song titled "Telepathy" featuring Nile Rodgers for the soundtrack of Netflix original series The Get Down in August 2016, contributed as a voice actress for The Emoji Movie, and was announced to had been cast for the upcoming film Zoe in May 2017.

Who is the father of Summer?
Aguilera became engaged to Rutler in February 2014.