Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van phan » van phong, van thanh, luan phan
phan duc » pham duc, phan tu, phan dau
su triet » su viet, ve triet
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
va hanh » van hanh, va thanh, va danh
hanh ve » hanh vi, hanh va, hanh kem
su tien » su kien, su hien, tu tieng
y nang » ky nang, ly nang, v nang

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

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