Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
lam duoc » nam duoc, luat duoc, lam thuoc
hieu van » hieu va, thien van, lieu va
hang ca » hang va, nang cao, hang tai
va hang » van hang, va nang, va lang
duoc va » nuoc va, duc va, duoc ma
van lam » van nam
ty hang » ly hang, ty xang, thi hang
ty lang » tay lang, ty xang, tu lang
cua tre » cua te, cuu tre, cua triet
ca cua » co cua

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) or (toc sach)) ((ty lang) or (ty hang)) xa hoi. hieu van lam duoc va hang ca cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ((ty lang) OR (ty hang)) xa hoi. hieu van lam duoc va hang ca cua tre.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ((ty lang) or (ty hang)) xa hoi. hieu van lam duoc va hang ca cua tre*.