Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
toc sach » hoc sach, thuoc sach, nuoc sach
thuoc va » thuc va, thuoc ma, thuong va
doc sach » hoc sach, nuoc sach, dac sac
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
bai cau » bai ca, ba cau, ban cau
bac cau » bach cau, ba cau, bac can
va cao » va cac, va co, va dao
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 sach) or (doc sach)) ky lang xa hoi. hieu va nam thuoc va cao ((bai cau) OR (bac cau)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ky lang xa hoi. hieu va nam thuoc va cao ((bai cau) OR (bac cau)) treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (doc sach)) ky lang xa hoi. hieu va nam thuoc va cao ((bai cau) OR (bac cau)) treo".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (doc sach)) ky lang xa hoi. hieu va nam thuoc va cao ((bai cau) OR (bac cau)) treo*.