Perhaps you should try some spelling variations:
su triet » su viet, ve triet
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty hang » ly hang, ty xang, thi hang
hang co » hang cho, hang ca, nang co
qua cau » quan cau, qua cac, qua ca
truc va » thuc va, thuc vat, trung va
su tien » su kien, su hien, tu tieng
co hoi » co hoc, co loi

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 ty hang co hoi. hieu qua cau ((truc va) or (hoc dan)) hanh vi ((su triet) or (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty hang co hoi. hieu qua cau ((truc va) OR (hoc dan)) hanh vi ((su triet) OR (su tien)).
• Adding a wildcard symbol may retrieve word variants: tu sach ty hang co hoi. hieu qua cau ((truc va) or (hoc dan)) hanh vi ((su triet) or (su tien))*.