Perhaps you should try some spelling variations:
cua triet » cua viet, va triet
tinh tien » trinh tien, tinh dien, minh tien
su triet » su viet, su tien, ve triet
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
nang ma » tang ma, sang ma, nang cao
thuc va » thuc vat, thuc dan, thuc day
va tinh » may tinh
ma hoi » mai hoi, xa hoi, ma hoa
sac ky » cac ky

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

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