Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
nghan dieu » nhan dieu, nhan dien, nha dieu
han dieu » nhan dieu, than dieu, lan dieu
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
lo van » le van, vo van, so van
cac lo » cac lop, cac co, cac bo

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ky ((nang xa) OR (nang ma)) hoi. hieu va cac lo van ((han dieu) or (nghan dieu)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky ((nang xa) OR (nang ma)) hoi. hieu va cac lo van ((han dieu) OR (nghan dieu)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ky ((nang xa) OR (nang ma)) hoi. hieu va cac lo van ((han dieu) or (nghan dieu)) cua tre".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky ((nang xa) OR (nang ma)) hoi. hieu va cac lo van ((han dieu) or (nghan dieu)) cua tre*.