Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nha thuoc, cay thuoc
thu sach » tu sach, thuat sach, thuoc sach
sach thu » sach thue, sach thieu, sach tham
sai cua » dai cua, hai cua, lai cua
dau sai » dau hai, dau tai, danh sai
cua tre » cua te, cuu tre, cua triet
bang va » hang va, ban va, trang va
bang xa » lang xa, mang xa, ang xa
va dau » va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach thu ((bang xa) OR (bang va)) hoi. lieu va ((nam thuoc) or (nam thu)) va dau sai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach thu ((bang xa) OR (bang va)) hoi. lieu va ((nam thuoc) OR (nam thu)) va dau sai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach thu ((bang xa) OR (bang va)) hoi. lieu va ((nam thuoc) or (nam thu)) va dau sai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach thu ((bang xa) OR (bang va)) hoi. lieu va ((nam thuoc) or (nam thu)) va dau sai cua tre*.