Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
ve triet » su triet
va trien » va truyen, va thiet, va tuyen
va thanh » gia thanh, ban thanh, va tinh
hieu van » hieu va, thien van, lieu va
cau duc » cao duc, cau luc, chu duc
te sach » toc sach
sach ky » sac ky, sach y, sach ty
van cau » van dau, van hau, van chat
co hoi » co hoc, co loi
o hoi » o hoc, o hai, o hoa

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 ky nang ((o hoi) OR (co hoi)). hieu van cau duc va thanh tai ((va trien) or (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ((o hoi) OR (co hoi)). hieu van cau duc va thanh tai ((va trien) OR (ve triet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ((o hoi) OR (co hoi)). hieu van cau duc va thanh tai ((va trien) or (ve triet))*".