Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tinh ket » dinh ket, tinh yeu, tinh yen
va trien » va truyen, va thiet, va tuyen
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va cam » va cham, va cac, va cao
tuc va » thuc va, truc va, duc va
ket va » ket van

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