Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
ban benh » san benh, ba benh, ban banh
benh di » benh dai, ben di, benh da
nam xua » nam cua, nam mua, nam qua
nam xuc » cam xuc, nam thuc, nam duoc
nang xa » lang xa, nang ma, mang xa
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
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 ((nang xa) or (nang x)) hoi. hieu van ((nam xuc) OR (nam xua)) ban benh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang xa) OR (nang x)) hoi. hieu van ((nam xuc) OR (nam xua)) ban benh di cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky ((nang xa) or (nang x)) hoi. hieu van ((nam xuc) OR (nam xua)) ban benh di cua tre*".