Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
thanh va » thanh van, thanh ha, thanh ve
thuoc va » thuc va, thuoc ma, thuong va
hanh va » hang va, hanh vi
sach ly » sach y, sach lo, sach ty
tu sach » thu sach, su sach, te sach
qua nam » quan nam, cua nam, quang nam
tang ma » tang van
cuu tre » cua tre, cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ly ((tang ma) OR (mang may)) hoi. hieu qua nam thuoc va ((thanh va) or (hanh va)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ly ((tang ma) OR (mang may)) hoi. hieu qua nam thuoc va ((thanh va) OR (hanh va)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ly ((tang ma) OR (mang may)) hoi. hieu qua nam thuoc va ((thanh va) or (hanh va)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ly ((tang ma) OR (mang may)) hoi. hieu qua nam thuoc va ((thanh va) or (hanh va)) cuu tre*.