Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cac truc » cau truc, cac tru, cac trung
so sach » so sanh, bo sach, co sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
truc va » thuc va, thuc vat, trung va
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
cuu tre » cua tre, cau treo
su sach » vu sach
y nang » ky nang, ly nang, v nang

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) y nang xa hoi. hieu va cac truc va danh vi ((cuu tre) OR (cau tren))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) y nang xa hoi. hieu va cac truc va danh vi ((cuu tre) OR (cau tren))~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) y nang xa hoi. hieu va cac truc va danh vi ((cuu tre) OR (cau tren))*.