Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van dinh » van minh, van dich, xuan dinh
cau tren » cu tren, dau tren, ca tren
hieu va » lieu va, hieu qua
cam tuc » cam xuc, cam tu, nam thuc
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
cuu tre » cua tre, cau treo
va dinh » va kinh, va tinh, vu dinh
ma hoi » mai hoi, xa hoi, ma hoa
va cam » va cham, va cac, va cao

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 ma hoi. hieu va cam tuc ((va dinh) or (van dinh)) du ((cuu tre) OR (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang ma hoi. hieu va cam tuc ((va dinh) OR (van dinh)) du ((cuu tre) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang ma hoi. hieu va cam tuc ((va dinh) or (van dinh)) du ((cuu tre) OR (cau tren))".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang ma hoi. hieu va cam tuc ((va dinh) or (van dinh)) du ((cuu tre) OR (cau tren))*.