Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dang xay » dang van, van xay
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
dan thi » dang thi, tran thi, dinh thi
cuu tre » cua tre, cau tren, cau treo
cu tren » tu tren, dua tren
thuc va » thuc vat, thuc dan, thuc day
xay hoi » xa hoi, tay hoi, cay phoi
y dang » ky dang, 2 dang, _ dang
cua te » cua tu
va dan » ca dan, va dao, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach y dang xay hoi. hieu van nam thuc va dan thi ((((cuu tre) or (cua te))) or (cu tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y dang xay hoi. hieu van nam thuc va dan thi ((((cuu tre) OR (cua te))) OR (cu tren)).
• Adding a wildcard symbol may retrieve word variants: toc sach y dang xay hoi. hieu van nam thuc va dan thi ((((cuu tre) or (cua te))) or (cu tren))*.