Perhaps you should try some spelling variations:
ve triet » va trien
hieu van » hieu va, thien van, lieu va
hang hoa » hang khoa, thanh hoa, hang va
su triet » su viet, su tien
vat hanh » vat thanh, van hanh, va hanh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va
hoa hoi » khoa hoi, hoa hoc, hoa doi
ky hang » ky nang, ly hang, ky dang
thuc » thu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky hang hoa hoi. ((hieu ve) or (hieu van)) am thuc vat hanh vi ((su triet) OR (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky hang hoa hoi. ((hieu ve) OR (hieu van)) am thuc vat hanh vi ((su triet) OR (ve triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky hang hoa hoi. ((hieu ve) or (hieu van)) am thuc vat hanh vi ((su triet) OR (ve triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky hang hoa hoi. ((hieu ve) or (hieu van)) am thuc vat hanh vi ((su triet) OR (ve triet))*.