Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
hanh tai » thanh tai, hang tai, han tai
va hanh » van hanh, va thanh, va danh
cam tuc » cam tu, nam thuc, dam thuc
hieu va » lieu va, hieu qua
so sach » so sanh, bo sach, co sach
ky dang » ky nang, ky danh
ky tang » ky nang, kho tang, ky trong
ma hoi » mai hoi, xa hoi, ma hoa
tai va » thai va, mai va, tri va

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ((ky tang) OR (ky dang)) ma hoi. hieu va ((cam tuc) or (cam xuc)) va hanh tai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((ky tang) OR (ky dang)) ma hoi. hieu va ((cam tuc) OR (cam xuc)) va hanh tai va triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((ky tang) OR (ky dang)) ma hoi. hieu va ((cam tuc) or (cam xuc)) va hanh tai va triet*".