Perhaps you should try some spelling variations:
cham quoc » chuan quoc, han quoc, cham soc
su triet » su viet, su tien, ve triet
ban hanh » ban hang
quoc ban » quoc bao, quoc lan, quoc quan
mai khoi » mai khoa, tai khoa, cac khoi
vuc nang » cuc nang, chuc nang, van nang
mai hoi » dai hoi, lai hoi, mai doi
hieu va » lieu va, hieu qua
va cham » va chat, va tham
vu nang » va nang, vu dang, v nang
hanh ki » hanh vi, hanh ky, hanh kien
tu sach » thu sach, su sach, te sach
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 ((vu nang) or (vuc nang)) ((mai hoi) or (mai khoi)). hieu va cham quoc ban hanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((vu nang) OR (vuc nang)) ((mai hoi) OR (mai khoi)). hieu va cham quoc ban hanh ki su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ((vu nang) or (vuc nang)) ((mai hoi) or (mai khoi)). hieu va cham quoc ban hanh ki su triet*.