Perhaps you should try some spelling variations:
cua triet » su triet, va triet
hieu van » hieu va, thien van, lieu va
cua viet » ca viet, hoa viet, cua vat
vu sach » vu bach, su sach, vu khach
co sach » bo sach, cuon sach, hoc sach
van cac » van hac, van cau, van bac
cac tuc » cac toc, cac tu, cac tac
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (co sach)) ky nang x ho. hieu van cac tuc va hanh di ((cua triet) OR (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (co sach)) ky nang x ho. hieu van cac tuc va hanh di ((cua triet) OR (cua viet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (co sach)) ky nang x ho. hieu van cac tuc va hanh di ((cua triet) OR (cua viet))*".