Perhaps you should try some spelling variations:
sach hoi » sach doi, sach moi, cach thoi
doanh va » doan va, doanh tai, doanh cua
thuc dan » thuc hanh, hoc dan, thuc vat
so sach » so sanh, bo sach, co sach
danh va » hanh va, anh va, dan va
cua tre » cua te, cuu tre, cua triet
thuc va » thuc vat, thuc day
va pham » van pham, va phat, va phap
hieu va » lieu va, hieu qua
hoi dan » hoa dan, hoc dan, hoi dap
dan xa » dan xac, dan xay, dan ca

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: so sach hoi dan xa hoi. hieu va pham ((thuc va) OR (thuc dan)) ((danh va) OR (doanh va)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach hoi dan xa hoi. hieu va pham ((thuc va) OR (thuc dan)) ((danh va) or (doanh va)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: so sach hoi dan xa hoi. hieu va pham ((thuc va) OR (thuc dan)) ((danh va) or (doanh va)) cua tre*.