Table schema:
CREATE TABLE table_27753492_2 (womens_doubles VARCHAR, mixed_doubles VARCHAR, tour VARCHAR)

Question: Who were the womens doubles when the mixed doubles were zhang nan zhao yunlei on the tour all england super series?
SQL: SELECT womens_doubles FROM table_27753492_2 WHERE mixed_doubles = "Zhang Nan Zhao Yunlei" AND tour = "All England Super Series"