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
tai cua » thai cua, tai cuc, tri cua
dau tai » dai tai, dat tai, da tai
cua tre » cua te, cuu tre, cua triet
lang ha » long ha
lang xa » dang xay, lang van
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 ((lang xa) OR (lang ha)) hoi. lieu va ((nam thuoc) or (nam thu)) va dau tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach thu ((lang xa) OR (lang ha)) hoi. lieu va ((nam thuoc) OR (nam thu)) va dau tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach thu ((lang xa) OR (lang ha)) hoi. lieu va ((nam thuoc) or (nam thu)) va dau tai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach thu ((lang xa) OR (lang ha)) hoi. lieu va ((nam thuoc) or (nam thu)) va dau tai cua tre*.