Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, hieu ve
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
truc va » thuc va, thuc vat, trung va
cua tre » cua te, cuu tre, cua triet
tuc va » thuc va, tuc xa, 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: thu sach ky nang xa hoi. ((hieu van) or (lieu va)) cac ((tuc va) OR (truc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang xa hoi. ((hieu van) OR (lieu va)) cac ((tuc va) OR (truc va)) hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang xa hoi. ((hieu van) or (lieu va)) cac ((tuc va) OR (truc va)) hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang xa hoi. ((hieu van) or (lieu va)) cac ((tuc va) OR (truc va)) hanh vi cua tre*.