Perhaps you should try some spelling variations:
van triet » va triet, van thiet, van trieu
va hanh » van hanh, va thanh, va danh
cam tuc » cam xuc, cam tu, nam thuc
hieu va » lieu va, hieu qua
su sach » so sach, vu sach
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
va dan » ca dan, va dao, va dau
va cam » va cham, va cac, va cao

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((nang xa) OR (nang ma)) hoi. hieu va cam tuc ((va hanh) OR (va dan)) vi van triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y ((nang xa) OR (nang ma)) hoi. hieu va cam tuc ((va hanh) or (va dan)) vi van triet~".
• Adding a wildcard symbol may retrieve word variants: su sach y ((nang xa) OR (nang ma)) hoi. hieu va cam tuc ((va hanh) or (va dan)) vi van triet*.