Perhaps you should try some spelling variations:
te sach » toc sach
sach ha » sach nha, sach han, sach xa
ha nang » kha nang, hoa nang, da nang
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
duc ban » duc tan, duc van, duc man
dua ban » dia ban, cua ban, qua ban
su viet » so viet
ve cac » va cac, vien cac
vi su » va su, ve su, ki su

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ha nang xa hoi. hieu ve cac ((duc ban) or (dua ban)) hanh vi su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ha nang xa hoi. hieu ve cac ((duc ban) OR (dua ban)) hanh vi su viet*.