Perhaps you should try some spelling variations:
dang xay » dang van
cam thuc » am thuc, nam thuc, cam thu
te sach » toc sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky ((mang may) or (((dang xay) or (van xay)))) hoi. hieu ve cam thuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((mang may) OR (((dang xay) OR (van xay)))) hoi. hieu ve cam thuc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach ky ((mang may) or (((dang xay) or (van xay)))) hoi. hieu ve cam thuc va hanh vi cua tre*.