Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
hieu van » hieu va, thien van, lieu va
hanh tai » thanh tai, hang tai, han tai
va triet » va thiet, va trien, ve triet
tu cach » tu cac
su sach » so sach, vu sach
nang ma » tang ma, sang ma, nang cao
xe hanh » ve hanh, de thanh, den hanh
ma hoi » mai hoi, xa hoi, ma hoa

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