Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
kien cau » khien cau, thien cau, ket cau
hien cau » khien cau, thien cau, hien cac
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va kinh » va tinh, qua kinh
va cam » va cham, va cac, va cao
xuc va » duc va, tuc va, luc va

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 xuc va kinh ((kien cau) or (hien cau)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. hieu va cam xuc va kinh ((kien cau) OR (hien cau)) tren.
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. hieu va cam xuc va kinh ((kien cau) or (hien cau)) tren*.