Perhaps you should try some spelling variations:
sach doi » sach hoi, sach moi, sach dao
doi nang » dai nang, hoi nang, voi nang
bo sach » co sach, hoc sach
cua tre » cua te, cuu tre, cua triet
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
van hai » van ha, van chat, van hanh
van hac » van hoc, van ha, van chat
nang xa » nang x, lang xa, nang ma
la tren » loai tren, dua tren, dat tren
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: bo sach doi nang xa hoi. thien ((van hac) or (van hai)) tuc va hanh va ((cua tre) or (la tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo sach doi nang xa hoi. thien ((van hac) OR (van hai)) tuc va hanh va ((cua tre) OR (la tren)).
• Adding a wildcard symbol may retrieve word variants: bo sach doi nang xa hoi. thien ((van hac) or (van hai)) tuc va hanh va ((cua tre) or (la tren))*.