Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
van cac » van hac, van cau, van bac
cac dac » cac dan, cac dai, cac bac
va hanh » va thanh, va danh, ban hanh
y nang » ky nang, ly nang, v nang

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 y nang xa hoi. hieu van cac dac ((va hanh) OR (van hanh)) lai su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang xa hoi. hieu van cac dac ((va hanh) OR (van hanh)) lai su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang xa hoi. hieu van cac dac ((va hanh) OR (van hanh)) lai su triet*.