Perhaps you should try some spelling variations:
hanh mai » hanh ma, hanh mau, hanh may
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
va cham » va chat, va tham
ma hoi » mai hoi, xa hoi, ma hoa
tuc va » thuc va, truc va, tuc xa

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 ma hoi. hieu va cham ((tuc va) or (duc va)) hanh mai va (thiet or thieu)~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ma hoi. hieu va cham ((tuc va) OR (duc va)) hanh mai va (thiet OR thieu).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ma hoi. hieu va cham ((tuc va) or (duc va)) hanh mai va (thiet or thieu)*.