Perhaps you should try some spelling variations:
trinh luong » trinh duong, trinh huong, trinh xuong
quang quang » quan quang, dang quang, dung quang
luong quan » thong quan, duong qua
quang van » quang ban, quang uan, quang va
hieu soat » hieu suat, hieu hoat, hieu luat
tien soat » trien hoat, thien hoat, kiem soat
van hieu » cao hieu
quan van » luan van, quan va, quan luan
van tien » toan tien, van tuan
tinh » dinh, minh, kinh

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

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