Perhaps you should try some spelling variations:
dua tren » dung tren
cham tuc » nham thuc, pham thuc, tham thuc
tu sach » thu sach, su sach, te sach
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
vu cham » va cham, vu kham, tu cham
hieu vu » hieu va, hieu ve, hieu su
xu lang » cu lang, xu dang, xu quang
tu lang » cu lang, tu lanh, tu quang
cuu tre » cua tre, cau tren, cau treo
tuc va » thuc va, truc va, tuc xa

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 ((tu lang) OR (xu lang)) xa hoi. hieu vu cham tuc va danh vi ((dua tren) OR (cuu tre))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((tu lang) OR (xu lang)) xa hoi. hieu vu cham tuc va danh vi ((dua tren) or (cuu tre))~".
• Adding a wildcard symbol may retrieve word variants: tu sach ((tu lang) OR (xu lang)) xa hoi. hieu vu cham tuc va danh vi ((dua tren) or (cuu tre))*.