Perhaps you should try some spelling variations:
trinh luong » trinh duong, trinh huong, trinh xuong
dang quang » dung quang, nang quan, dang hung
tinh dang » tinh dung, binh dang, tinh sang
hieu soat » hieu suat, hieu hoat, hieu luat
tien soat » trien hoat, thien hoat, kiem soat
quang ma » xquang ma, quang va, quang manh
quan van » luan van, quan va, quan doan
ma hieu » va hieu, ma sieu, manh hieu

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

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