Perhaps you should try some spelling variations:
chat quoc » chuan quoc, thuat quoc, han quoc
chan benh » can benh, khang benh, kham benh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
va chat » van chat, va phat, cao chat
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang xa hoi. lieu va chat quoc ((chan benh) OR (chua benh)) vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. lieu va chat quoc ((chan benh) OR (chua benh)) vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. lieu va chat quoc ((chan benh) OR (chua benh)) vi ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. lieu va chat quoc ((chan benh) OR (chua benh)) vi ((cua tre) or (cuu tre))*.