Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
su triet » su viet, ve triet
thi hang » thi hanh, thi nang, thi hong
hanh cao » hanh cac, hanh cat, hanh cad
tu sach » thu sach, su sach, tu cach
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
su tien » su kien, su hien, tu tieng
hieu ve » hieu va, hieu van
hang xa » hoang xa, hang va, hang ca
te sach » toc sach
ve cam » ve cham, ve cac, va cam

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