Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cau theo » cau thi, cau tao
tan hoi » dan hoi, tao hoi, tay hoi
hoi hoc » hoa hoc, khoa hoc, hoi chuc
hieu va » lieu va, hieu qua
cac xuc » cam xuc, cac nuoc, chat xuc
va hanh » van hanh, va thanh, va danh
hai cau » hai chau, hai chu, hai hau
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
ky tan » ky tang, k tan, ky dan

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ky tan hoi hoc. hieu va cac xuc ((va hanh) or (ban thanh)) hai cau theo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky tan hoi hoc. hieu va cac xuc ((va hanh) OR (ban thanh)) hai cau theo.
• Adding a wildcard symbol may retrieve word variants: su sac ky tan hoi hoc. hieu va cac xuc ((va hanh) or (ban thanh)) hai cau theo*.