Perhaps you should try some spelling variations:
hieu san » hieu van, hieu sau, chieu sang
van hanh » van thanh, ban hanh, van anh
su triet » su viet, ve triet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
su tien » su kien, su hien, tu tieng
pham » phan
tuan » quan, tran, luan

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang xa hoi. hieu san pham duc ((van hanh) or (tuan anh)) di ((su triet) OR (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu san pham duc ((van hanh) OR (tuan anh)) di ((su triet) OR (su tien))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. hieu san pham duc ((van hanh) or (tuan anh)) di ((su triet) OR (su tien))*".