Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
va triet » va thiet, va trien, ve triet
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
xuc va » tuc va, luc va, xac va
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 nang xa hoi. hieu va cam ((xuc va) OR (duc va)) hanh vi ((cua te) OR (va triet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ky nang xa hoi. hieu va cam ((xuc va) OR (duc va)) hanh vi ((cua te) or (va triet))~".
• Adding a wildcard symbol may retrieve word variants: doc sach ky nang xa hoi. hieu va cam ((xuc va) OR (duc va)) hanh vi ((cua te) or (va triet))*.