Perhaps you should try some spelling variations:
nhan loc » nhan luc, nhan hoc, nhan loai
hanh doi » thanh doi, hanh noi, hang doi
mai khoi » mai khoa, tai khoa, cac khoi
qua nhan » cua nhan, qua nhat, qua phan
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cua triet, dua tren
su sach » so sach, vu sach
mai hoi » dai hoi, lai hoi, mai doi
cuu tre » cau tren, cau treo
loc va » hoc va, luc va
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 y nang ((mai hoi) OR (mai khoi)). hieu qua nhan loc va hanh doi ((cua tre) OR (cuu tre))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang ((mai hoi) OR (mai khoi)). hieu qua nhan loc va hanh doi ((cua tre) or (cuu tre))~".
• Adding a wildcard symbol may retrieve word variants: su sach y nang ((mai hoi) OR (mai khoi)). hieu qua nhan loc va hanh doi ((cua tre) or (cuu tre))*.