Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
nam thuc » nam thuoc, am thuc, nam thu
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
va hanh » van hanh, va thanh, va danh
co sach » bo sach, cuon sach, hoc sach
cam tuc » cam xuc, cam tu, dam thuc
hieu va » lieu va, hieu qua
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: co sach ky nang x hoi. hieu va ((cam tuc) OR (nam thuc)) va hanh vi ((cua tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach ky nang x hoi. hieu va ((cam tuc) OR (nam thuc)) va hanh vi ((cua tre) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach ky nang x hoi. hieu va ((cam tuc) OR (nam thuc)) va hanh vi ((cua tre) or (cau tren))".
• Adding a wildcard symbol may retrieve word variants: co sach ky nang x hoi. hieu va ((cam tuc) OR (nam thuc)) va hanh vi ((cua tre) or (cau tren))*.