Perhaps you should try some spelling variations:
thuc dan » thuc hanh, hoc dan, thuc vat
dang xay » dang van, van xay
toc sac » toc sach, toc san, hoc sach
vai cuu » vai cua
dan vai » dan va, dan tai, dan vat
thuc va » thuc vat, thuc day
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
lang xa » lang ha, lang van
sac ky » cac ky, sai ky
va nam » van nam, ha nam, va nay

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 ky ((lang xa) OR (dang xay)) hoi. hieu va nam ((thuc va) or (thuc dan)) dan vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sac ky ((lang xa) OR (dang xay)) hoi. hieu va nam ((thuc va) OR (thuc dan)) dan vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sac ky ((lang xa) OR (dang xay)) hoi. hieu va nam ((thuc va) or (thuc dan)) dan vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: toc sac ky ((lang xa) OR (dang xay)) hoi. hieu va nam ((thuc va) or (thuc dan)) dan vai cuu tre*.