Perhaps you should try some spelling variations:
cua triet » su triet, va triet
cua viet » ca viet, hoa viet, cua vat
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac
dan chi » danh chi, dan thi, van chi
y nang » ky nang, ly nang, v nang
me hoi » le hoi
tuc va » thuc va, truc va, tuc xa
va dan » ca dan, va dao, va dau

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 y nang ((me hoi) or (ma hoa)). hieu va cac tuc va dan chi ((cua triet) OR (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang ((me hoi) OR (ma hoa)). hieu va cac tuc va dan chi ((cua triet) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang ((me hoi) or (ma hoa)). hieu va cac tuc va dan chi ((cua triet) OR (cua viet))".
• Adding a wildcard symbol may retrieve word variants: su sach y nang ((me hoi) or (ma hoa)). hieu va cac tuc va dan chi ((cua triet) OR (cua viet))*.