Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
hanh tai » thanh tai, hang tai, han tai
sang tao » hang tai
va hanh » van hanh, va thanh, va danh
cam tuc » cam tu, nam thuc, dam thuc
sach ky » sac ky, sach y, sach ty
so sach » so sanh, bo sach, co sach
sang ma » tang ma, nang ma, mang may
hieu va » lieu va, hieu qua
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 ((sang ma) OR (sang tao)) 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 ((sang ma) OR (sang tao)) 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 ((sang ma) OR (sang tao)) hoi. hieu va ((cam tuc) or (cam xuc)) va hanh tai va triet*".