Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
sach ty » sach tu, sach thu, xach tay
tang co » tang cho, nang co, tang o
qua cac » cua cac
cac vuc » cac nuoc, cac vung, cac cuoc
vuc van » duc van, luc van, thuc van
cua cau » cua cac, cua chu, cua cay
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ty) or (sach y)) tang co hoc. hieu qua cac vuc van hanh vi cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ty) OR (sach y)) tang co hoc. hieu qua cac vuc van hanh vi cua cau*.