Perhaps you should try some spelling variations:
sach van » sach han, sach va, bach van
van nang » van quang, van ban, van dong
van hanh » van thanh, ban hanh, van anh
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
xuc van » duc van, luc van, vuc van
hanh va » hang va, hanh vi
va cam » va cham, va cao, va cai

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 van nang xa hoi. hieu ((va cam) or (va cac)) xuc van hanh va su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach van nang xa hoi. hieu ((va cam) OR (va cac)) xuc van hanh va su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach van nang xa hoi. hieu ((va cam) or (va cac)) xuc van hanh va su triet*.