Perhaps you should try some spelling variations:
hieu vien » hieu hien, thieu nien, hieu tieng
hieu viec » nhieu viec, hieu ve, sieu viet
sach nuoc » sach duoc, cac nuoc, bach tuoc
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang
di cuu » di cau, di cua, dinh cuu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang xa hoi. ((hieu vien) OR (hieu viec)) sach nuoc va hanh di cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang xa hoi. ((hieu vien) OR (hieu viec)) sach nuoc va hanh di cuu tre".
• Adding a wildcard symbol may retrieve word variants: su sach y nang xa hoi. ((hieu vien) OR (hieu viec)) sach nuoc va hanh di cuu tre*.