CREATE TABLE table_30306 ("Year Location" TEXT, "Mens Singles" TEXT, "Womens Singles" TEXT, "Mens Doubles" TEXT, "Womens Doubles" TEXT)

Who is listed under mens singles when womens has wang nan zhang yining?
SELECT "Mens Singles" FROM table_30306 WHERE "Womens Doubles" = 'Wang Nan Zhang Yining'
SELECT "Mens Singles" FROM "table_30306" WHERE "Womens Doubles" = 'Wang Nan Zhang Yining'