Perhaps you should try some spelling variations:
nang cau » nang cao, hang cau, nang dau
sach ky » sac ky, sach ty, sach kem
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
tuc va » truc va, tuc xa, duc va
vi cua » vai cua, di cua
va cam » va cham, va cac, va cao

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 y)) nang cau hoi. hieu va cam ((tuc va) or (thuc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach y)) nang cau hoi. hieu va cam ((tuc va) OR (thuc va)) hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach y)) nang cau hoi. hieu va cam ((tuc va) or (thuc va)) hanh vi cua tre*.