Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
duc manh » suc manh, duc anh, duc minh
va triet » va thiet, va trien, ve triet
su triet » su viet, su tien, 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
duc van » duc va, duc tan, duc phan

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 van cham ((duc van) OR (duc manh)) hanh vi ((va triet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu van cham ((duc van) OR (duc manh)) hanh vi ((va triet) OR (su triet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. hieu van cham ((duc van) OR (duc manh)) hanh vi ((va triet) or (su triet))*".