Perhaps you should try some spelling variations:
su triet » su viet, su tien
ve triet » va trien
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
cao hoi » co hoi, cao hoc, tao hoi
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
va nam » van nam, ha nam, va nay
nam tu » nam thu, nam thuc

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