Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve 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 tuc » cac toc, cac tu, cac tac
va hanh » van hanh, va thanh, va danh
ma hoi » mai hoi, xa hoi, ma hoa
tuc va » thuc va, truc va, tuc xa
vi va » vi van, vai va, vu va

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 tuc va hanh vi va triet~.
• 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 tuc va hanh vi va triet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (vu sach)) ky nang ma hoi. hieu va cac tuc va hanh vi va triet*.