Perhaps you should try some spelling variations:
cau trieu » cac trieu, chua trieu, cau dieu
cau triet » su triet, cua triet, va triet
toc sach » hoc sach, doc sach, thuoc sach
hieu va » lieu va
sach ky » sac ky, sach y, sach ty
va danh » va dinh, va dan, va hanh
danh va » doanh va, hanh va, anh va
thi toc » thi tac, thi goc, thi loc
toc va » hoc va, toc ta, tuc va
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 ky nang x hoi. ((hieu va) or (hieu qua)) thi toc va danh va ((cau triet) OR (cau trieu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang x hoi. ((hieu va) OR (hieu qua)) thi toc va danh va ((cau triet) OR (cau trieu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang x hoi. ((hieu va) or (hieu qua)) thi toc va danh va ((cau triet) OR (cau trieu))".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang x hoi. ((hieu va) or (hieu qua)) thi toc va danh va ((cau triet) OR (cau trieu))*.