"1947-11-21Z"^^ . "1947Z"^^ . . . . . "Yvonne S. Thornton (born November 21, 1947) is an American obstetrician-gynecologist, musician and author, best known for her memoir, The Ditchdigger's Daughters."@en . . . . "Thornton, Yvonne Shirley"@en . . . . "Yvonne S. Thornton"@en . "Americanobstetrician-gynecologist,author" .