Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
ma hoi » mai hoi, xa hoi, me hoi
va cam » va cham, va cac, va cao
cam tu » cam thu, nam tu, dam tu

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