Perhaps you should try some spelling variations:
luong quan » thong quan, duong qua
tinh luong » tinh huong, dinh luong, minh luong
tinh dung » trinh dung, tin dung, tinh quang
dung hung » dung chung, dung nhung, dung huong
hieu soat » hieu suat, hieu hoat, hieu luat
hung van » phung van, nhung van, dung van
van hieu » cao hieu
van kiem » va kiem, van hien, tac kiem
van kien » van tien, van hien, van chien

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( tinh dung hung van hieu soat ) or ( tinh luong quan ((van kiem) OR (van kien)) toan ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung hung van hieu soat ) OR ( tinh luong quan ((van kiem) OR (van kien)) toan ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh dung hung van hieu soat ) or ( tinh luong quan ((van kiem) OR (van kien)) toan ))*".