CREATE TABLE "german_open" (
  "year_location" text,
  "mens_singles" text,
  "womens_singles" text,
  "mens_doubles" text,
  "womens_doubles" text
);

Question: Who won Womens Singles in the year that Ma Lin won Mens Singles?
SQL: SELECT "womens_singles" FROM "german_open" WHERE "mens_singles"='Ma Lin';