Perhaps you should try some spelling variations:
sach daon » sach danh, sach dat, sach han
van hanh » van thanh, ban hanh, van anh
sach dao » lanh dao
su triet » su viet, su tien, ve triet
hieu van » hieu va, thien van, lieu va
van cac » van hac, van cau, van bac
luc van » luoc van, luu van, duc van
cac luc » cau luc, coc luc, cac nuoc
nang xa » nang x, lang xa, nang ma
su hien » su kien, su tien, thu hien

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 luc van hanh vi ((su triet) or (su hien))~.
• 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 luc van hanh vi ((su triet) OR (su hien)).
• Adding a wildcard symbol may retrieve word variants: tu ((sach daon) or (sach dao)) nang xa hoi. hieu van cac luc van hanh vi ((su triet) or (su hien))*.