Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
va thanh » gia thanh, ban thanh, va tinh
hieu van » hieu va, thien van, lieu va
su triet » su viet, su tien, ve triet
nang ho » nang hoc, nang co, tang ho
sach ky » sach y, sach ty, sach kem
van cau » van dau, van hau, van chat
cau duc » cao duc, cau luc, chu duc
ho hoi » hoc hoi, hoa hoi, hoi hoi
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((sach ky) OR (sac ky)) nang ho hoi. hieu van cau duc va thanh tai ((va thiet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach ky) OR (sac ky)) nang ho hoi. hieu van cau duc va thanh tai ((va thiet) OR (su triet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach ky) OR (sac ky)) nang ho hoi. hieu van cau duc va thanh tai ((va thiet) or (su triet))*".