Perhaps you should try some spelling variations:
cau triet » cau trieu, su triet, cua triet
van hang » van khang, van hoang, van thang
toc sach » hoc sach, doc sach, thuoc sach
hieu va » lieu va, hieu qua
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
cuu tre » cua tre, cau tren, cau treo
va hang » va nang, va lang, va hanh
va cam » va cham, va cac, va cao
cam tu » cam thu, nam tu, dam tu
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 nang x hoi. hieu va cam tu ((va hang) OR (van hang)) di ((cuu tre) or (cau triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tu nang x hoi. hieu va cam tu ((va hang) OR (van hang)) di ((cuu tre) OR (cau triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach tu nang x hoi. hieu va cam tu ((va hang) OR (van hang)) di ((cuu tre) or (cau triet))".
• Adding a wildcard symbol may retrieve word variants: toc sach tu nang x hoi. hieu va cam tu ((va hang) OR (van hang)) di ((cuu tre) or (cau triet))*.