Perhaps you should try some spelling variations:
trien cong » thien cong
trinh han » trinh quan
giang van » hoang van, gian dan, giang day
hieu soat » hieu suat, hieu hoat, hieu luat
tien soat » trien hoat, thien hoat, kiem soat
dang van » hoang van, hang va
cong nam » dong nam, uong nam, thong nam
van tien » toan tien, van hieu, 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 han ((giang van) or (dang van)) hieu soat ) or ( trien cong nam van tien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh han ((giang van) OR (dang van)) hieu soat ) OR ( trien cong nam van tien soat )).
• Adding a wildcard symbol may retrieve word variants: (( trinh han ((giang van) or (dang van)) hieu soat ) or ( trien cong nam van tien soat ))*.