Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
nam thuc » nam thuoc, am thuc, nam thu
hanh va » hang va
hieu ca » hieu cac, hieu cua, hieu va
sach ty » sach y, sach tu, xach tay
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet
ca nam » cua nam, cai nam, ha nam

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((sach ty) or (sach thu)) lang xa hoi. hieu ca nam thuc vat ((hanh va) or (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach ty) OR (sach thu)) lang xa hoi. hieu ca nam thuc vat ((hanh va) OR (hanh vi)) cua tre.
• Adding a wildcard symbol may retrieve word variants: toc ((sach ty) or (sach thu)) lang xa hoi. hieu ca nam thuc vat ((hanh va) or (hanh vi)) cua tre*.