Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh do
nhan luc » nang luc
qua nhan » cua nhan, qua nhat, qua phan
hanh doi » hanh noi, hang doi, hanh moi
so sach » so sanh, bo sach, co sach
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2
luc va » duc va, tuc va, loc va
ma hoi » mai hoi, ma hoa, me hoi
v nang » va nang, vu nang, van 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: so sach v nang ((ma hoi) OR (xa hoi)). hieu qua nhan luc va ((hanh doi) OR (thanh doi)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach v nang ((ma hoi) OR (xa hoi)). hieu qua nhan luc va ((hanh doi) or (thanh doi)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: so sach v nang ((ma hoi) OR (xa hoi)). hieu qua nhan luc va ((hanh doi) or (thanh doi)) cua tre*.