Perhaps you should try some spelling variations:
tinh luong » tinh huong, dinh luong, minh luong
luong quan » thong quan, duong qua
hieu soat » hieu hoat, hieu luat, kiem soat
hieu suat » hieu luat, hieu qua
quang uan » quang tuan, quang ban, quang tran
van chien » van hien, van hieu, van tien
chien van » thien van, chien va, chi van
quan van » luan van, quan va, quan luan
uan van » luan van, tan van, san van

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tinh luong quan van ((hieu soat) or (hieu suat)) ) or ( tinh quang uan van chien van ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh luong quan van ((hieu soat) OR (hieu suat)) ) OR ( tinh quang uan van chien van )).
• Adding a wildcard symbol may retrieve word variants: (( tinh luong quan van ((hieu soat) or (hieu suat)) ) or ( tinh quang uan van chien van ))*.