Perhaps you should try some spelling variations:
quoc ban » quoc bao, quoc lan, quoc quan
cam quoc » cac quoc, cao quoc, nam quoc
su sach » so sach, vu sach
cuu tre » cau tren, cau treo
ban anh » ban hanh, ban banh, ban danh
cua tre » cua te, cua triet, dua tren
hieu va » lieu va, hieu qua
y nang » ky nang, ly nang, v nang
anh ve » hanh ve, anh va, anh viet
va cam » va cham, va cac, va cao
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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 ((x hoi) OR (o hoi)). hieu va cam quoc ban anh ve ((cuu tre) OR (cua tre))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang ((x hoi) OR (o hoi)). hieu va cam quoc ban anh ve ((cuu tre) OR (cua tre))".
• Adding a wildcard symbol may retrieve word variants: su sach y nang ((x hoi) OR (o hoi)). hieu va cam quoc ban anh ve ((cuu tre) OR (cua tre))*.