Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
van hanh » van thanh, ban hanh, van anh
va triet » va thiet, va trien, ve triet
sach ky » sac ky, sach y, sach ty
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
hieu va » lieu va, hieu qua
xuc van » duc van, luc van, vuc van
ma hoi » mai hoi, xa hoi, ma hoa
va cam » va cham, va cac, va cao
cua te » cua tu

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ky tang ma hoi. hieu va cam xuc van hanh vi ((cua te) OR (va triet))~.
• Adding a wildcard symbol may retrieve word variants: doc sach ky tang ma hoi. hieu va cam xuc van hanh vi ((cua te) or (va triet))*.