Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
nam quoc » nam duoc, nam buoc, nhap quoc
hieu van » hieu va, thien van, lieu va
ban benh » san benh, ba benh, ban banh
dang xay » dang van, van xay
benh vi » benh va, benh ve, benh li
te sach » toc sach
lang xa » lang ha, lang van
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y ((lang xa) or (dang xay)) hoi. hieu van ((nam quoc) OR (nam thuoc)) ban benh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y ((lang xa) OR (dang xay)) hoi. hieu van ((nam quoc) OR (nam thuoc)) ban benh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y ((lang xa) or (dang xay)) hoi. hieu van ((nam quoc) OR (nam thuoc)) ban benh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach y ((lang xa) or (dang xay)) hoi. hieu van ((nam quoc) OR (nam thuoc)) ban benh vi cua tre*.