Perhaps you should try some spelling variations:
cau triet » cau trieu, su triet, cua triet
cau treo » cau theo, cau tren, cau trieu
va hanh » van hanh, va thanh, va danh
cac toc » cac toi, cac nuoc, cac thoi
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
va nang » van nang, da nang, cam nang
so sanh » do sanh
qua cac » cua cac
toc va » hoc va, toc ta, tuc va

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) or (so sanh)) va nang xa hoi. hieu qua cac toc va hanh vi ((cau treo) OR (cau triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sanh)) va nang xa hoi. hieu qua cac toc va hanh vi ((cau treo) OR (cau triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sanh)) va nang xa hoi. hieu qua cac toc va hanh vi ((cau treo) OR (cau triet))".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sanh)) va nang xa hoi. hieu qua cac toc va hanh vi ((cau treo) OR (cau triet))*.