Question: When was the retired American Olympic gymnast which was recruited to Paul Ziert born? 
Context: Taniko Nakamura-Mitsukuri (中村-三栗 多仁子, born March 23, 1943) is a retired Japanese gymnast.  She competed in all artistic gymnastics events at the 1964 and 1968 Olympics and won a team bronze medal in 1964.  Her best individual achievement was seventh place on uneven bars in 1968.  Born Taniko Nakamura she changed her last name after marrying Takashi Mitsukuri, a fellow Olympic gymnast. Toshiko Shirasu-Aihara (白須-相原 俊子, born June 3, 1939) is a retired Japanese gymnast.  She competed in all artistic gymnastics events at the 1960 and 1964 Olympics and won a team bronze medal in 1964.  Her best individual achievements were fourth places on the vault and uneven bars in 1964.  Born Toshiko Shirasu she changed her last name after marrying Nobuyuki Aihara, a fellow Olympic gymnast.  Their son Yutaka Aihara won a bronze medal in gymnastics at the 1992 Olympics. Viktor Yakovlevich Klimenko (Russian: Виктор Яковлевич Клименко , born 25 February 1949) is a retired Russian gymnast.  He competed for the Soviet Union at the 1968 and 1972 Olympics and won a team silver medal on each occasion.  Individually he earned a bronze medal in parallel bars in 1968, as well as a gold medal in pommel horse and a silver medal in vault in 1972.  At the world championships Klimenko collected four medals in 1970–1974.  His wife Larisa Petrik is also a former Olympic gymnast. Jaycie Lynn Phelps (born September 26, 1979 in Greenfield, Indiana, United States) is a retired American Olympic gymnast and member of the 1996 Olympic gold medal U.S. women's gymnastics team, the Magnificent Seven.  She is known for her consistency and clean lines in her gymnastics. Marie Roethlisberger (born May 12, 1966) is a former gymnast who was a 1984 United States Olympic gymnastics alternate.  She is almost completely deaf.  She is the daughter of United States 1968 Olympic Gymnast Fred Roethlisberger and the sister of 1992, 1996, and 2000 Olympic gymnast John Roethlisberger.  She was selected as a 1991 NCAA Top VI Award (now Top VIII) winner as one of the six top NCAA student-athletes and the 1991 female Walter Byers Scholarship winner as the National Collegiate Athletic Association's top scholar-athlete. Irma Pezzia Haubold (November 20, 1908 – April 4, 1996) was an American artistic gymnast.  She competed at the 1936 Summer Olympics and placed fifth with the team.  She was married to a fellow Olympic gymnast Frank Haubold.  They were the first married couple of compete in the same Olympics. Bart Conner (born March 28, 1958) is a retired American Olympic gymnast.  As a member of the men's gymnastics team at the 1984 Summer Olympic Games, Conner won two gold medals.  He currently owns and operates the Bart Conner Gymnastics Academy in Norman, Oklahoma, along with his wife, Romanian Olympic gold medalist Nadia Comăneci.  In addition, both Comăneci and Conner are highly involved with the Special Olympics. Paul Elbert Hamm (born September 24, 1982 in Washburn, Wisconsin) is a retired American artistic gymnast.  He is a World Champion gymnast and three-time Olympic medalist.  He is the 2003 World all-around champion, and he won the all-around competition at the 2004 Olympic Games.  He is the most successful American male gymnast, and the only male American gymnast to win all-around at World's and the Olympics. Paul Ziert is a former University of Oklahoma gymnastics coach.  Ziert recruited Bart Conner to the school.  In 1977 and 1978, Ziert's teams won the NCAA Men's Gymnastics championship. Ernestine Jean Russell (born June 10, 1938), later known by her married names Ernestine Carter and Ernestine Weaver, is a Canadian former gymnast and American former college gymnastics coach.  She represented Canada in the 1956 and 1960 Summer Olympics.  Although Russell won no medals in her two Olympic appearances, she is regarded as Canada's first notable female Olympic gymnast and contributed significantly to the growing popularity of women's gymnastics in Canada and the United States.
Answer: March 28, 1958