Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
su triet » su viet, ve triet
nang hoa » nang hoat, hang hoa, nang hoc
hanh ve » hanh vi, hanh va, hanh kem
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
su tien » su kien, su hien, tu tieng
sach ky » sach y, sach ty, sach kem
hieu he » hieu ve, hiem he, hieu le
hoa hoi » khoa hoi, hoa hoc, hoa doi
sac ky » cac ky, sai 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 ((sach ky) OR (sac ky)) nang hoa hoi. hieu he nam thuc va hanh ve ((su triet) or (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang hoa hoi. hieu he nam thuc va hanh ve ((su triet) OR (su tien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sac ky)) nang hoa hoi. hieu he nam thuc va hanh ve ((su triet) or (su tien))".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sac ky)) nang hoa hoi. hieu he nam thuc va hanh ve ((su triet) or (su tien))*.