Perhaps you should try some spelling variations:
dat thanh » dao thanh, dat khanh, dang thanh
cau triet » cau trieu, su triet, cua triet
nam thuc » nam thuoc, am thuc, nam tu
thanh vi » hanh vi, thanh va, thanh ve
te sach » toc sach
co sach » bo sach, cuon sach, hoc sach
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
ma hoi » mai hoi, xa hoi, ma hoa
vi cau » va cau, ve cau, di cau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (co sach)) ky nang ma hoi. hieu va ((nam thuc) OR (nam thu)) dat thanh vi cau triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (co sach)) ky nang ma hoi. hieu va ((nam thuc) OR (nam thu)) dat thanh vi cau triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (co sach)) ky nang ma hoi. hieu va ((nam thuc) OR (nam thu)) dat thanh vi cau triet".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (co sach)) ky nang ma hoi. hieu va ((nam thuc) OR (nam thu)) dat thanh vi cau triet*.