Perhaps you should try some spelling variations:
va triet » va trien, ve triet, cua triet
tu sach » thu sach, su sach, te sach
vu sach » vu bach, su sach, vu khach
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
cac toc » cac toi, cac nuoc, cac thoi
va hanh » van hanh, va thanh, va danh
ma hoi » mai hoi, xa hoi, ma hoa
toc va » hoc va, toc ta, tuc va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (vu sach)) ky nang ma hoi. hieu va cac toc va hanh vi ((va triet) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (vu sach)) ky nang ma hoi. hieu va cac toc va hanh vi ((va triet) OR (va thiet)).
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (vu sach)) ky nang ma hoi. hieu va cac toc va hanh vi ((va triet) or (va thiet))*.