Perhaps you should try some spelling variations:
sach daon » sach danh, sach dat, sach han
sach dao » lanh dao
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
nang xa » nang x, lang xa, nang ma
van cac » van hac, van cau, van bac
cac xuc » cam xuc, cac nuoc, chat xuc
xuc van » duc van, luc van, vuc van
su viet » so viet
kien » bien, vien, tien

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach daon) or (sach dao)) nang xa hoi. hieu van cac xuc van hanh vi ((su viet) or (su kien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach daon) OR (sach dao)) nang xa hoi. hieu van cac xuc van hanh vi ((su viet) OR (su kien)).
• Adding a wildcard symbol may retrieve word variants: tu ((sach daon) or (sach dao)) nang xa hoi. hieu van cac xuc van hanh vi ((su viet) or (su kien))*.