Perhaps you should try some spelling variations:
trinh gian » trinh giang, trinh giao, trinh giai
gian lang » gian dan
hieu soat » hieu suat, hieu hoat, hieu luat
kiem soat » kiem toan
lang cao » nang cao, lang co, quang cao
dung nam » dong nam, dung lam, sung nam
van kiem » va kiem, van kien, van hieu
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 gian lang cao hieu soat ) or ( tin dung nam van kiem soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh gian lang cao hieu soat ) OR ( tin dung nam van kiem soat )).
• Adding a wildcard symbol may retrieve word variants: (( trinh gian lang cao hieu soat ) or ( tin dung nam van kiem soat ))*.