Perhaps you should try some spelling variations:
thien van » thi van
cau tren » cu tren, dau tren, ca tren
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
nam tuc » nam thuc, nam truc, nam tu
va hanh » van hanh, va thanh, va danh
cuu tre » cua tre, cau treo
tuc va » thuc va, truc va, tuc xa
x hoi » xa hoi, o hoi, x ho

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 nang x hoi. ((hieu va) OR (thien van)) nam tuc va hanh vi ((cuu tre) OR (cau tren))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang x hoi. ((hieu va) or (thien van)) nam tuc va hanh vi ((cuu tre) OR (cau tren))~".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang x hoi. ((hieu va) or (thien van)) nam tuc va hanh vi ((cuu tre) OR (cau tren))*.