Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, te sach, tu cach
vai cuu » vai cua
dua ban » dia ban, cua ban, qua ban
cau dua » cau qua, cau cua, ca dua
van cau » van dau, van hau, van chat
cuu tre » cua tre, cau tren, cau treo
mai hoi » mai khoi, dai hoi, lai hoi
ly vang » ly hang, ly van, ly quang
su sach » so sach, vu sach

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) OR (su sach)) ly vang ((mai hoi) OR (ma hoa)). hieu van cau dua ban thanh vai cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ly vang ((mai hoi) or (ma hoa)). hieu van cau dua ban thanh vai cuu tre~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ly vang ((mai hoi) or (ma hoa)). hieu van cau dua ban thanh vai cuu tre*.