Perhaps you should try some spelling variations:
ban benh » san benh, ba benh, ban banh
quoc ban » quoc bao, quoc lan, quoc quan
va cham » va chat, va tham
benh di » benh dai, ben di, benh da
cua tre » cua te, cuu tre, cua triet
sach ky » sach y, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
va cam » va cac, va cao, va cai
sac ky » cac ky, sai ky
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) or (sac ky)) nang xa hoi. lieu ((va cam) OR (va cham)) quoc ban benh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sac ky)) nang xa hoi. lieu ((va cam) OR (va cham)) quoc ban benh di cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) or (sac ky)) nang xa hoi. lieu ((va cam) OR (va cham)) quoc ban benh di cua tre*".