Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
thuc dan » thuc hanh, hoc dan, thuc vat
cam thuc » am thuc, nam thuc, cam thu
hanh di » hanh de, hang di, danh di
sach ty » sach y, sach tu, sach thu
lang xa » lang ha, dang xay, lang van
van cam » van nam, van lam, van cau

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