Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
cac tuc » cac toc, cac tu, cac tac
hieu va » lieu va, hieu qua
hieu ve » hieu van
tu sach » thu sach, te sach, tu cach
nang ma » tang ma, sang ma, nang cao
su sach » so sach, vu sach
ma hoi » mai hoi, xa hoi, ma hoa
tuc va » thuc va, truc va, tuc xa
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va
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 (su sach)) ky nang ma hoi. ((hieu ve) or (hieu va)) cac tuc va dan vi va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang ma hoi. ((hieu ve) OR (hieu va)) cac tuc va dan vi va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ky nang ma hoi. ((hieu ve) or (hieu va)) cac tuc va dan vi va triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ky nang ma hoi. ((hieu ve) or (hieu va)) cac tuc va dan vi va triet*.