Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
su triet » su viet, ve triet
thuc va » thuc vat, thuc dan, thuc day
hanh ve » hanh vi, hanh va, hanh kem
va hanh » van hanh, va thanh, va danh
su sach » so sach, vu sach
hieu he » hieu ve, hiem he, hieu le
hoa hoi » khoa hoi, hoa hoc, hoa doi
ky tang » ky dang, kho tang, ky trong
su tien » su kien, su hien, tu tieng
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: su sach ((ky tang) OR (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: su sach ((ky tang) OR (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: "su sach ((ky tang) OR (ky nang)) hoa hoi. hieu he nam thuc va hanh ve ((su triet) or (su tien))".
• Adding a wildcard symbol may retrieve word variants: su sach ((ky tang) OR (ky nang)) hoa hoi. hieu he nam thuc va hanh ve ((su triet) or (su tien))*.