Perhaps you should try some spelling variations:
thanh vi » hanh vi, thanh va, thanh ve
su sach » so sach, vu sach
sach tu » sach thu, cach tu, sach ty
duc van » duc va, duc tan, duc manh
duc ban » duc tan, dua ban, duc man
ca viet » va viet, co viet, hoa viet
tu xang » ty xang, tu lang, tu quang
va cam » va cham, va cac, va cao
ve cac » va cac, vien cac
xang x » nang x
x hoi » xa hoi, o hoi, x ho
vi ca » vit ca, li ca, va ca

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach tu xang x hoi. hieu ((ve cac) or (va cam)) ((duc ban) OR (duc van)) thanh vi ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu xang x hoi. hieu ((ve cac) OR (va cam)) ((duc ban) OR (duc van)) thanh vi ca viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach tu xang x hoi. hieu ((ve cac) or (va cam)) ((duc ban) OR (duc van)) thanh vi ca viet".
• Adding a wildcard symbol may retrieve word variants: su sach tu xang x hoi. hieu ((ve cac) or (va cam)) ((duc ban) OR (duc van)) thanh vi ca viet*.