Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
day thuc » dan thuc, dai thuc, dam thuc
cay thuc » cay thuoc, can thuc, cach thuc
vat cuu » vat cua
dan vat » dang vat, van vat, dan va
van dan » van ban, ban dan, van dao
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
hoc cac » hoc cao

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) or (hoc cac)) ky lang xa hoi. hieu va ((day thuc) or (cay thuc)) van dan vat cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc cac)) ky lang xa hoi. hieu va ((day thuc) OR (cay thuc)) van dan vat cuu tre.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (hoc cac)) ky lang xa hoi. hieu va ((day thuc) or (cay thuc)) van dan vat cuu tre*.