Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
va hanh » van hanh, va thanh, va danh
sach ky » sach y, sach ty, sach kem
hieu va » lieu va, hieu qua
cam tuc » cam xuc, cam tu, nam thuc
sac ky » cac ky, sai ky
va cam » va cham, va cac, va cao
va dau » va dao
x hoi » xa hoi, o hoi, x ho
vu va » vu van, tu va, su va

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 ky) OR (sac ky)) nang x hoi. hieu va cam tuc ((va hanh) OR (va dau)) vu va triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sac ky)) nang x hoi. hieu va cam tuc ((va hanh) or (va dau)) vu va triet~".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sac ky)) nang x hoi. hieu va cam tuc ((va hanh) or (va dau)) vu va triet*.