Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
pham thuc » phap thuc, pham chuc, nham thuc
nang cau » nang cao, hang cau, nang dau
hieu van » hieu va, thien van, lieu va
cham tuc » nham thuc, tham thuc, cham soc
hanh vai » hanh vi, hanh va, hanh tai
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
va hanh » van hanh, va thanh, va danh
vai va » mai va, dai va, hai va
thiet » thieu

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

• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ty nang cau hoi. hieu van ((cham tuc) OR (pham thuc)) va hanh vai va thiet~.
• Adding a wildcard symbol may retrieve word variants: thuoc sach ty nang cau hoi. hieu van ((cham tuc) or (pham thuc)) va hanh vai va thiet*.