Perhaps you should try some spelling variations:
mai khoi » mai khoa, tai khoa, cac khoi
cau phuc » cau truc, chau phu, huu phuc
hieu van » hieu va, thien van, lieu va
va triet » va thiet, va trien, ve triet
mai hoi » dai hoi, lai hoi, mai doi
van cau » van dau, van hau, van chat
co sach » bo sach, cuon sach, hoc sach
phuc va » phuc vu, thuc va, chuc va
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
su sach » so sach, vu sach
y nang » ky nang, ly nang, v nang
vi va » vi van, vai va, vu va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (co sach)) y nang ((mai hoi) OR (mai khoi)). hieu van cau phuc va danh vi va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (co sach)) y nang ((mai hoi) OR (mai khoi)). hieu van cau phuc va danh vi va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (co sach)) y nang ((mai hoi) OR (mai khoi)). hieu van cau phuc va danh vi va triet".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (co sach)) y nang ((mai hoi) OR (mai khoi)). hieu van cau phuc va danh vi va triet*.