Perhaps you should try some spelling variations:
day thanh » dao thanh, dat thanh, dam thanh
cam thuc » am thuc, nam thuc, cam thu
da thanh » dao thanh, dat thanh, dam thanh
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
hang ca » nang cao, hang tai, hang dau
va cua » va chua, via cua, ca cua
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty ((hang ca) OR (hang va)) hoi. hieu va cam thuc ((day thanh) or (da thanh)) va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((hang ca) OR (hang va)) hoi. hieu va cam thuc ((day thanh) OR (da thanh)) va cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty ((hang ca) OR (hang va)) hoi. hieu va cam thuc ((day thanh) or (da thanh)) va cua tre*".