Perhaps you should try some spelling variations:
cau triet » cau trieu, su triet, cua triet
sach thu » sach thue, sach thieu, sach tham
hieu va » lieu va, hieu qua
sach tu » cach tu, sach ty, sach uu
va hang » van hang, va nang, va lang
hang vi » hang va, hanh vi, hang di
cuu tre » cua tre, cau tren, cau treo
cam tu » cam thu, nam tu, dam tu
va cam » va cham, va cac, va cao
x hoi » xa hoi, o hoi, x ho

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)) nang x hoi. hieu va cam tu va hang vi ((cuu tre) or (cau triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach tu) OR (sach thu)) nang x hoi. hieu va cam tu va hang vi ((cuu tre) OR (cau triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach tu) OR (sach thu)) nang x hoi. hieu va cam tu va hang vi ((cuu tre) or (cau triet))".
• Adding a wildcard symbol may retrieve word variants: toc ((sach tu) OR (sach thu)) nang x hoi. hieu va cam tu va hang vi ((cuu tre) or (cau triet))*.