Perhaps you should try some spelling variations:
dang xay » dang van, van xay
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
dang cay » dang ca, dang cac, dung cay
thuc va » thuc vat, thuc dan, thuc day
hieu va » lieu va, hieu qua
toc sac » toc san, hoc sach, doc sach
cua tre » cua te, cuu tre, cua triet
va nam » van nam, ha nam, va nay
va dan » ca dan, va dao, va dau
dan va » doan va, dan ca, ban va
va cua » va chua, via cua, ca cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sac) OR (toc sach)) ky ((dang cay) or (dang xay)) phoi. hieu va nam thuc va dan va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sac) OR (toc sach)) ky ((dang cay) OR (dang xay)) phoi. hieu va nam thuc va dan va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sac) OR (toc sach)) ky ((dang cay) or (dang xay)) phoi. hieu va nam thuc va dan va cua tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sac) OR (toc sach)) ky ((dang cay) or (dang xay)) phoi. hieu va nam thuc va dan va cua tre*.