Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
hang cho » sang cho, hang khoa, phong cho
cac thuc » cach thuc, cac thu, can thuc
cua cay » cua cac
hieu ve » hieu va, hieu van
cho hoc » co hoc, khoa hoc
ty hang » ly hang, ty xang, thi hang
cua chu » sua chua
ve cac » va cac, vien cac

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ty hang cho hoc. hieu ve cac thuc dan hanh vi ((cua cay) OR (cua chu))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ty hang cho hoc. hieu ve cac thuc dan hanh vi ((cua cay) or (cua chu))~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ty hang cho hoc. hieu ve cac thuc dan hanh vi ((cua cay) or (cua chu))*.