Perhaps you should try some spelling variations:
cach trinh » hanh trinh, sach tranh, cac tinh
trinh cong » trinh dung
sach nganh » sach ngan, sach tranh, sach danh
cac nganh » hoc nganh
cong khi » cong thai, khong khi, co khi
cong tan » cong tac, cong san, cong thanh
tu cach » tu cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu cach trinh cong khi đong luc ) or ( te ((sach nganh) OR (cac nganh)) cong tan đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu cach trinh cong khi đong luc ) OR ( te ((sach nganh) OR (cac nganh)) cong tan đong luc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu cach trinh cong khi đong luc ) or ( te ((sach nganh) OR (cac nganh)) cong tan đong luc ))".
• Adding a wildcard symbol may retrieve word variants: (( tu cach trinh cong khi đong luc ) or ( te ((sach nganh) OR (cac nganh)) cong tan đong luc ))*.