Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tinh duc » minh duc, ninh duc, sinh duoc
dinh duc » minh duc, ninh duc, sinh duoc
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, pham duc
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cuu tre » cua tre, cau tren, cau treo
cu tren » tu tren, dua tren
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 xa hoi. hieu va cam duc va ((dinh duc) OR (tinh duc)) ((cuu tre) or (cu tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. hieu va cam duc va ((dinh duc) OR (tinh duc)) ((cuu tre) OR (cu tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang xa hoi. hieu va cam duc va ((dinh duc) OR (tinh duc)) ((cuu tre) or (cu tren))".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. hieu va cam duc va ((dinh duc) OR (tinh duc)) ((cuu tre) or (cu tren))*.