Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
van cau » van dau, van hau, van chat
cau tuc » cau truc, cau tu, cau luc
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
su sach » so sach, vu sach
ma hoi » xa hoi, me hoi, va hoi
tuc va » thuc va, truc va, tuc xa
di cua » dai cua, doi cua, de cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((((ma hoi) OR (ma hoa))) OR (mai hoi)). hieu van cau tuc va hanh di cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ((((ma hoi) OR (ma hoa))) or (mai hoi)). hieu van cau tuc va hanh di cua triet~".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((((ma hoi) OR (ma hoa))) or (mai hoi)). hieu van cau tuc va hanh di cua triet*.