Perhaps you should try some spelling variations:
dua tren » dung tren
vat dung » van dung, viet dung, mat duong
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
va dung » van dung, va duong, va ung
cao tuc » dao tuc, cao duc, cao suc
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
cuu tre » cua tre, cau tren, cau treo
va cao » va cac, va co, va dao

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: vu sach ky nang xa hoi. hieu va cao tuc ((va dung) OR (vat dung)) co ((dua tren) OR (cuu tre))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang xa hoi. hieu va cao tuc ((va dung) OR (vat dung)) co ((dua tren) or (cuu tre))~".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang xa hoi. hieu va cao tuc ((va dung) OR (vat dung)) co ((dua tren) or (cuu tre))*.