Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
cau treo » cau theo, cau tren, cau triet
sach ky » sac ky, sach y, sach ty
su sach » so sach, vu sach
cam tuc » cam xuc, cam tu, nam thuc
nang ma » tang ma, sang ma, nang cao
va danh » va dinh, va hanh, dia danh
va dan » ca dan, va dao, va dau
va cam » va cham, va cac, va cao
ma hoi » mai hoi, xa hoi, ma hoa

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 ky nang ma hoi. lieu va cam tuc ((va danh) OR (va dan)) hai ((cau treo) or (dau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ma hoi. lieu va cam tuc ((va danh) OR (va dan)) hai ((cau treo) OR (dau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ma hoi. lieu va cam tuc ((va danh) OR (va dan)) hai ((cau treo) or (dau tren))".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ma hoi. lieu va cam tuc ((va danh) OR (va dan)) hai ((cau treo) or (dau tren))*.