Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
va triet » va thiet, va trien, ve triet
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
bo sach » co sach, hoc sach
thuc va » thuc vat, thuc dan, thuc day
va hang » van hang, va nang, va lang
hang di » hang doi, hang vi, hang dien
te sach » toc sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (bo sach)) ky dang xa hoi. hieu van nam thuc va hang di ((cua triet) OR (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (bo sach)) ky dang xa hoi. hieu van nam thuc va hang di ((cua triet) OR (va triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (bo sach)) ky dang xa hoi. hieu van nam thuc va hang di ((cua triet) OR (va triet))".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (bo sach)) ky dang xa hoi. hieu van nam thuc va hang di ((cua triet) OR (va triet))*.