Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
truc va » thuc vat, trung va
thuc va » thuc vat, thuc dan, thuc day
ma hoi » mai hoi, xa hoi, ma hoa
ve cam » ve cham, ve cac, va cam
dai va » mai 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: su sach ky nang ma hoi. hieu ve cam ((truc va) or (thuc va)) hanh dai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ma hoi. hieu ve cam ((truc va) OR (thuc va)) hanh dai va thiet.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ma hoi. hieu ve cam ((truc va) or (thuc va)) hanh dai va thiet*.