Perhaps you should try some spelling variations:
hieu van » thien van, lieu va
danh vai » danh sai, danh va, doanh van
tu sach » thu sach, su sach, te sach
vai cua » dai cua, hai cua, lai cua
va danh » va dinh, va dan, va hanh
cao duc » dao duc, cao suc, giao duc
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
sach ly » sach y, sach lo, sach ty
nang ma » tang ma, sang ma, nang cao
ly nang » ky nang, ly hang, ly vang
ma hoi » mai hoi, xa hoi, ma hoa

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 ly nang ma hoi. ((((hieu ve) or (hieu van))) or (hieu va)) cao duc va danh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ly nang ma hoi. ((((hieu ve) OR (hieu van))) OR (hieu va)) cao duc va danh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ly nang ma hoi. ((((hieu ve) or (hieu van))) or (hieu va)) cao duc va danh vai cua tre*.