Perhaps you should try some spelling variations:
doanh vang » doanh van, doanh sang, doanh quang
hieu van » hieu va, thien van, lieu va
vang cua » mang cua, hang cua, tang cua
te sach » toc sach
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
van lam » van nam
duoc va » nuoc va, duoc ma, duong va
cua tre » cua te, cuu tre, cua triet

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky lang xa hoi. hieu van lam ((duoc va) or (duc va)) doanh vang cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky lang xa hoi. hieu van lam ((duoc va) OR (duc va)) doanh vang cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach ky lang xa hoi. hieu van lam ((duoc va) or (duc va)) doanh vang cua tre*.