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