How many Grand Slam titles were won by the defending champion of the 1981 US Open - Women's Doubles?  
1981 US Open – Women's Doubles: Billie Jean King and Martina Navratilova were the defending champions but only Navratilova competed that year with Pam Shriver. Billie Jean King:  King won 39 Grand Slam titles: 12 in singles, 16 in women's doubles, and 11 in mixed doubles.
i don't know