Perhaps you should try some spelling variations:
sach tham » sach nha
tang luan » dung luan
tham nuoc » thay nuoc, thoat nuoc, nha nuoc
hoang van » hang va
va hanh » van hanh, va thanh, va danh
va tham » van tham, va cham, va thanh
so sach » so sanh, bo sach, co sach
hieu va » lieu va, hieu qua
cua su » qua su
cua cu » cua chu, cua cau, cua co

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach tham ((tang luan) or (hoang van)) hoe. hieu va tham nuoc va hanh vi ((cua su) or (cua cu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach tham ((tang luan) OR (hoang van)) hoe. hieu va tham nuoc va hanh vi ((cua su) OR (cua cu)).
• Adding a wildcard symbol may retrieve word variants: so sach tham ((tang luan) or (hoang van)) hoe. hieu va tham nuoc va hanh vi ((cua su) or (cua cu))*.