Perhaps you should try some spelling variations:
thanh dong » thanh duong, thanh cong, hanh dong
day thanh » dao thanh, dat thanh, da thanh
toc sach » hoc sach, doc sach, thuoc sach
dong cua » dung cua, cong cua, huong cua
thuc day » thuc dan, thuc vat
nam thuc » nam thuoc, am thuc, nam thu
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
long ha » dong ha, cong ha, dong hoa
lang xa » dang xay, lang van

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky ((lang xa) or (((lang ha) OR (long ha)))) hoi. hieu van nam thuc day thanh dong cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky ((lang xa) OR (((lang ha) OR (long ha)))) hoi. hieu van nam thuc day thanh dong cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky ((lang xa) or (((lang ha) OR (long ha)))) hoi. hieu van nam thuc day thanh dong cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky ((lang xa) or (((lang ha) OR (long ha)))) hoi. hieu van nam thuc day thanh dong cua tre*.