Question: Which player has had more singles appearances, Casey Dellacqua or Olga Morozova? 
Sentence (from "Olga Morozova"): Olga Vasilyevna Morozova (Russian: Ольга Васильевна Морозова ) (born 22 February 1949) is a retired female tennis player who competed for the Soviet Union.
Relevant evidence: No