Perhaps you should try some spelling variations:
lam duoc » nam duoc, luat duoc, lam thuoc
hieu van » hieu va, thien van, lieu va
duoc va » nuoc va, duc va, duoc ma
hanh va » hang va, hanh vi
danh va » doanh va, anh va, dan va
te sach » toc sach
van lam » van nam
ky lang » ky dang, ky tang, tay lang
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) or (ky nang)) xa hoi. hieu van lam duoc va ((danh va) OR (hanh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ky lang) OR (ky nang)) xa hoi. hieu van lam duoc va ((danh va) OR (hanh va)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ky lang) or (ky nang)) xa hoi. hieu van lam duoc va ((danh va) OR (hanh va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ((ky lang) or (ky nang)) xa hoi. hieu van lam duoc va ((danh va) OR (hanh va)) cua tre*.