Perhaps you should try some spelling variations:
thien van » thi van
hieu van » hieu va, lieu va, hieu ve
hanh dai » hanh tai, hanh dao, vanh dai
va hanh » van hanh, va thanh, va danh
cac tac » cac toc, cac bac, cac dac
vu sach » vu bach, su sach, vu khach
nang ma » tang ma, sang ma, nang cao
so sach » so sanh, bo sach, co sach
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
y nang » ky nang, ly nang, v nang
tac va » tac da, tac xa, tuc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (so sach)) y nang ma hoi. ((hieu van) or (thien van)) cac tac va hanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (so sach)) y nang ma hoi. ((hieu van) OR (thien van)) cac tac va hanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (so sach)) y nang ma hoi. ((hieu van) or (thien van)) cac tac va hanh dai cua tre*.