Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
cac nuoc » hoc nuoc, dat nuoc, cua nuoc
doan van » doan va, hoang van, luan van
cap nuoc » dat nuoc
van cua » vang cua, ban cua, dan cua
va doan » va doanh, van doan, va dan
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
ty mang » ty hang, tin mang, tri mang

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ((ty mang) or (ty xang)) xa hoi. hieu ve ((cac nuoc) or (cap nuoc)) va doan van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ((ty mang) OR (ty xang)) xa hoi. hieu ve ((cac nuoc) OR (cap nuoc)) va doan van cua tre.
• Adding a wildcard symbol may retrieve word variants: thuat sach ((ty mang) or (ty xang)) xa hoi. hieu ve ((cac nuoc) or (cap nuoc)) va doan van cua tre*.