Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
ban thanh » ban hanh, ban hang
bai luan » bai toan, li luan, vay luan
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
vai cuu » vai cua
cay qua » cau qua, cac qua, cay lua
ky tang » ky nang, ky dang, kho tang
ky sang » ky nang, ky dang, duy sang
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 ((ky sang) OR (ky tang)) ma hoa. hieu van ((cay qua) or (bai luan)) ban thanh vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky sang) OR (ky tang)) ma hoa. hieu van ((cay qua) OR (bai luan)) ban thanh vai cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky sang) OR (ky tang)) ma hoa. hieu van ((cay qua) or (bai luan)) ban thanh vai cuu tre*".