Perhaps you should try some spelling variations:
van hanh » van thanh, van anh, van ban
ban hanh » ban hang
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
su hien » su kien, thu hien, nhu hien
tu sach » thu sach, su sach, te sach
sach vu » sach va, sach tu, sach uu
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
vu nang » vuc nang, va nang, vu dang
su tien » su kien, tu tieng, dau tien

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: tu sach vu nang xa hoi. hieu va cac nuoc ((van hanh) OR (ban hanh)) ve ((su hien) OR (su tien))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach vu nang xa hoi. hieu va cac nuoc ((van hanh) or (ban hanh)) ve ((su hien) OR (su tien))~".
• Adding a wildcard symbol may retrieve word variants: tu sach vu nang xa hoi. hieu va cac nuoc ((van hanh) or (ban hanh)) ve ((su hien) OR (su tien))*.