Perhaps you should try some spelling variations:
trinh quan » trinh luat, trinh han
hieu soat » hieu suat, hieu hoat, hieu luat
tien soat » trien hoat, thien hoat, kiem soat
lang van » dang van, tang van, hoang van
van hieu » cao hieu
dung nam » dong nam, dung lam, sung nam
van tien » toan tien, van tuan
nam van » nam dan, nam va, pham van

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( ((trinh quan) OR (tinh quang)) lang van hieu soat ) or ( tin dung nam van tien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((trinh quan) OR (tinh quang)) lang van hieu soat ) OR ( tin dung nam van tien soat )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((trinh quan) OR (tinh quang)) lang van hieu soat ) or ( tin dung nam van tien soat ))".
• Adding a wildcard symbol may retrieve word variants: (( ((trinh quan) OR (tinh quang)) lang van hieu soat ) or ( tin dung nam van tien soat ))*.