Perhaps you should try some spelling variations:
su triet » su viet, ve triet
sang mai » sang ma, sang tai, lang mai
su tien » su kien, su hien, tu tieng
hanh ca » hanh cac, hanh cat, hanh cua
va hanh » van hanh, va thanh, va danh
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ky sang » ky nang, ky dang, ky tang
su sach » so sach, vu sach
soc va » hoc va, loc va, doc va
su sac » su cac, su xac

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sac) OR (su sach)) ky sang mai hoi. hieu ve cham soc va hanh ca ((su triet) or (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sac) OR (su sach)) ky sang mai hoi. hieu ve cham soc va hanh ca ((su triet) OR (su tien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sac) OR (su sach)) ky sang mai hoi. hieu ve cham soc va hanh ca ((su triet) or (su tien))".
• Adding a wildcard symbol may retrieve word variants: ((su sac) OR (su sach)) ky sang mai hoi. hieu ve cham soc va hanh ca ((su triet) or (su tien))*.