Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
cham tuc » nham thuc, pham thuc, tham thuc
hanh vai » hanh vi, hanh va, hanh tai
sach ky » sac ky, sach ty, sach kem
cao hoi » cau hoi, co hoi, cao hoc
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
tuc va » thuc va, truc va, tuc xa
vai va » mai va, dai va, hai va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ky) or (sach y)) nang cao hoi. ((hieu van) OR (hieu va)) cham tuc va hanh vai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach y)) nang cao hoi. ((hieu van) OR (hieu va)) cham tuc va hanh vai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sach y)) nang cao hoi. ((hieu van) OR (hieu va)) cham tuc va hanh vai va thiet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sach y)) nang cao hoi. ((hieu van) OR (hieu va)) cham tuc va hanh vai va thiet*.