Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
toc sach » hoc sach, doc sach, thuoc sach
cam thuc » am thuc, nam thuc, cam thu
dong mau » dong ma, dang mau, dong ha
dong nam » dong ha, dong tai, dong va
va thanh » gia thanh, va tinh, le thanh
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
va cua » va chua, via cua, ca cua
ve cam » ve cham, ve cac, va cam

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 ty ((dong mau) or (dong nam)) hoi. hieu ve cam thuc ((va thanh) OR (ban thanh)) va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty ((dong mau) OR (dong nam)) hoi. hieu ve cam thuc ((va thanh) OR (ban thanh)) va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ty ((dong mau) or (dong nam)) hoi. hieu ve cam thuc ((va thanh) OR (ban thanh)) va cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ty ((dong mau) or (dong nam)) hoi. hieu ve cam thuc ((va thanh) OR (ban thanh)) va cua tre*.