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, hanh vi
cua tre » cuu tre, cua triet, dua tren
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
sach tu » cach tu, sach ty, sach uu
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
va nam » van nam, ha nam, va nay
cua te » cua tu

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 tu) or (sach thu)) lang xa hoi. hieu va nam thuc va hanh va ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach tu) OR (sach thu)) lang xa hoi. hieu va nam thuc va hanh va ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach tu) or (sach thu)) lang xa hoi. hieu va nam thuc va hanh va ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: toc ((sach tu) or (sach thu)) lang xa hoi. hieu va nam thuc va hanh va ((cua tre) OR (cua te))*.