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
hieu van » hieu va, thien van, lieu va
vu dang » su dang, vu quang, cua dang
vu nang » vuc nang, va nang, v nang
su sach » so sach, vu sach
van am » van nam, van lam, van dam
x hoi » xa hoi, o hoi, x ho

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 ((vu nang) OR (vu dang)) x hoi. hieu van am thuc dan hanh vi ((cua triet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((vu nang) OR (vu dang)) x hoi. hieu van am thuc dan hanh vi ((cua triet) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((vu nang) OR (vu dang)) x hoi. hieu van am thuc dan hanh vi ((cua triet) or (su triet))".
• Adding a wildcard symbol may retrieve word variants: su sach ((vu nang) OR (vu dang)) x hoi. hieu van am thuc dan hanh vi ((cua triet) or (su triet))*.