Perhaps you should try some spelling variations:
cua triet » cua viet, va triet
su triet » su viet, su tien, ve triet
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
cac thuc » cach thuc, cac thu, can thuc
hieu van » hieu va, thien van, lieu va
ly quang » le quang, vu quang
van cac » van hac, van cau, van bac
su sach » so sach, vu sach
ca hoi » cau hoi, cua hoi, xa hoi

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 ((ly hang) or (ly quang)) ca hoi. hieu van cac thuc dan hanh vi ((cua triet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ly hang) OR (ly quang)) ca hoi. hieu van cac thuc dan hanh vi ((cua triet) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: su sach ((ly hang) or (ly quang)) ca hoi. hieu van cac thuc dan hanh vi ((cua triet) or (su triet))*.