Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
hieu ve » hieu van
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa
soc va » hoc va, loc va, goc va
doc va » duoc va, hoc va, duc va
vi cua » vai cua, di cua

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 y nang ma hoi. ((hieu ve) or (hieu va)) cham ((soc va) or (doc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ma hoi. ((hieu ve) OR (hieu va)) cham ((soc va) OR (doc va)) hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ma hoi. ((hieu ve) or (hieu va)) cham ((soc va) or (doc va)) hanh vi cua tre*.