Perhaps you should try some spelling variations:
ve triet » va trien, su triet
vat hanh » vat thanh, van hanh, va hanh
nam thuc » nam thuoc, am thuc, nam thu
hang hoa » hang khoa, thanh hoa, hang va
su vien » su viet, su kien, su hien
hieu he » hieu ve, hiem he, hieu le
hoa hoi » khoa hoi, hoa hoc, hoa doi
sac ky » cac ky
he nam » ha nam, nghe nam

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sac ky) or (sai ky)) hang hoa hoi. hieu he nam thuc vat hanh vi ((ve triet) or (su vien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sac ky) OR (sai ky)) hang hoa hoi. hieu he nam thuc vat hanh vi ((ve triet) OR (su vien)).
• Adding a wildcard symbol may retrieve word variants: tu ((sac ky) or (sai ky)) hang hoa hoi. hieu he nam thuc vat hanh vi ((ve triet) or (su vien))*.