Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
den hanh » den thanh, dan hanh, deu hanh
tu cach » tu cac
su sach » so sach, vu sach
cao hoi » cau hoi, co hoi, cao hoc
xe hanh » ve hanh, de thanh, deu hanh
tai cua » thai cua, tai cuc, tri cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cach) or (su sach)) ky nang cao hoi. hieu van nam thu ((xe hanh) OR (den hanh)) tai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (su sach)) ky nang cao hoi. hieu van nam thu ((xe hanh) OR (den hanh)) tai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cach) or (su sach)) ky nang cao hoi. hieu van nam thu ((xe hanh) OR (den hanh)) tai cua triet".
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (su sach)) ky nang cao hoi. hieu van nam thu ((xe hanh) OR (den hanh)) tai cua triet*.