Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
sach van » sach han, sach va, bach van
van nang » van quang, van ban, van dong
hanh ve » hanh va, hanh kem
dua ban » dia ban, cua ban, qua ban
su viet » so viet
duc ban » duc tan, duc van, duc man
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
ve cac » va cac, vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach van nang xa hoi. hieu ve cac ((duc ban) or (dua ban)) ((hanh ve) OR (hanh vi)) su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach van nang xa hoi. hieu ve cac ((duc ban) OR (dua ban)) ((hanh ve) OR (hanh vi)) su viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach van nang xa hoi. hieu ve cac ((duc ban) or (dua ban)) ((hanh ve) OR (hanh vi)) su viet*".