Perhaps you should try some spelling variations:
lam duoc » nam duoc, luat duoc, lam thuoc
hieu van » hieu va, thien van, lieu va
van cua » vang cua, ban cua, dan cua
va danh » va dinh, va hanh, dia danh
te sach » toc sach
van lam » van nam
ky tang » ky nang, ky dang, kho tang
ky lang » ky nang, ky dang, tay lang
cua tre » cua te, cuu tre, cua triet
va dan » ca dan, va dao, va dau

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 tang)) xa hoi. hieu van lam duoc ((va danh) OR (va dan)) van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ky lang) OR (ky tang)) xa hoi. hieu van lam duoc ((va danh) OR (va dan)) van cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ky lang) or (ky tang)) xa hoi. hieu van lam duoc ((va danh) OR (va dan)) van cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ((ky lang) or (ky tang)) xa hoi. hieu van lam duoc ((va danh) OR (va dan)) van cua tre*.