Perhaps you should try some spelling variations:
thuc dan » thuc hanh, hoc dan, thuc vat
su triet » su viet, ve triet
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
su tien » su kien, su hien, tu tieng
sach ty » sach y, sach tu, sach thu
truc va » thuc va, thuc vat, trung va
van dau » van dao, phan dau
xang co » nang co, lang co, tang co
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 xang co hoi. hieu van dau ((truc va) or (thuc dan)) hanh vi ((su triet) or (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty xang co hoi. hieu van dau ((truc va) OR (thuc dan)) hanh vi ((su triet) OR (su tien)).
• Adding a wildcard symbol may retrieve word variants: tu sach ty xang co hoi. hieu van dau ((truc va) or (thuc dan)) hanh vi ((su triet) or (su tien))*.