Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thi cong » tai cong, thien cong
lam duoc » nam duoc, luat duoc, lam thuoc
hieu van » hieu va, thien van, lieu va
chua tre » chua tri, cua tre, chua trieu
tay lang » tai lang, tay tang, tay quang
ty hang » ly hang, ty xang, thi hang
van lam » van nam
duoc va » nuoc va, duc va, duoc ma
va nang » van nang, da nang, cam nang
nang va » nang van, hang va, nang ma
va chua » vua chua, ca chua, va chu

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((tay lang) or (((ty hang) or (thi cong)))) xa hoi. hieu van lam duoc va nang va chua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((tay lang) OR (((ty hang) OR (thi cong)))) xa hoi. hieu van lam duoc va nang va chua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ((tay lang) or (((ty hang) or (thi cong)))) xa hoi. hieu van lam duoc va nang va chua tre*.