Perhaps you should try some spelling variations:
ban benh » ba benh, ban banh, can benh
hieu van » hieu va, thien van, lieu va
cam quoc » cac quoc, cao quoc, han quoc
san benh » sau benh, tai benh, so benh
nam quoc » nam duoc, nam buoc, nam thuoc
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky nang x hoi. hieu van ((cam quoc) OR (nam quoc)) ((ban benh) or (san benh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang x hoi. hieu van ((cam quoc) OR (nam quoc)) ((ban benh) OR (san benh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang x hoi. hieu van ((cam quoc) OR (nam quoc)) ((ban benh) or (san benh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang x hoi. hieu van ((cam quoc) OR (nam quoc)) ((ban benh) or (san benh)) vi cua tre*.