Perhaps you should try some spelling variations:
thien van » thi van
nang cau » nang cao, hang cau, nang dau
hieu van » hieu va, lieu va, hieu ve
cham tuc » nham thuc, pham thuc, tham thuc
danh vai » danh sai, danh va, doanh van
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
va danh » va dinh, va dan, va hanh
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 nang cau hoi. ((hieu van) or (thien van)) cham tuc va danh vai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang cau hoi. ((hieu van) OR (thien van)) cham tuc va danh vai va thiet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang cau hoi. ((hieu van) or (thien van)) cham tuc va danh vai va thiet*.