Perhaps you should try some spelling variations:
sach trinh » sach tranh, hanh trinh, sach kinh
trinh cong » trinh dung
cac nganh » hoc nganh
nganh co » nganh cong, nganh hoa, nganh y
toc sach » hoc sach, doc sach, thuoc sach
cong tac » cong ty
te cac » tu cac, ve cac, te cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( te cac nganh co khi đong luc ) or ( toc sach trinh cong tac đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( te cac nganh co khi đong luc ) OR ( toc sach trinh cong tac đong luc ))*.