Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
sach vua » sach va, sach cua, sach luan
vua sang » bua sang, cua sang, lua sang
hanh ki » hanh vi, hanh ky, hanh kien
cuc ban » cua ban, cac ban, cuu ban
luc ban » duc ban, luc bat, luc van
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
mai hoi » mai khoi, dai hoi, lai hoi
va cham » va chat, va tham
ma hoi » xa hoi, ma hoa, me hoi
ki su » ky su

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 vua sang ((ma hoi) or (mai hoi)). hieu va cham ((luc ban) OR (cuc ban)) hanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach vua sang ((ma hoi) OR (mai hoi)). hieu va cham ((luc ban) OR (cuc ban)) hanh ki su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach vua sang ((ma hoi) or (mai hoi)). hieu va cham ((luc ban) OR (cuc ban)) hanh ki su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach vua sang ((ma hoi) or (mai hoi)). hieu va cham ((luc ban) OR (cuc ban)) hanh ki su triet*.