Perhaps you should try some spelling variations:
bach thuoc » bach tuoc, cach thuc, ban thuoc
hieu vien » hieu hien, hieu viec, thieu nien
thuoc va » thuc va, thuoc ma, thuong va
hanh vai » hanh va, hanh tai, hanh van
tu sach » thu sach, su sach, te sach
ky sang » ky dang, ky tang, duy sang
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky sang) OR (ky nang)) ma hoi. hieu vien bach thuoc va ((hanh vai) OR (hanh vi)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky sang) or (ky nang)) ma hoi. hieu vien bach thuoc va ((hanh vai) OR (hanh vi)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky sang) or (ky nang)) ma hoi. hieu vien bach thuoc va ((hanh vai) OR (hanh vi)) cua tre*.