Perhaps you should try some spelling variations:
thanh vai » thanh van, thanh tai, thanh oai
thanh hai » thanh phan, thanh hoa, thanh san
thu sach » thuat sach, thuoc sach, thu hoach
hieu van » hieu va, thien van, lieu va
tu sach » su sach, te sach, tu cach
dua ban » dia ban, cua ban, qua ban
cua tre » cua te, cuu tre, cua triet
sang ma » tang ma, nang ma, sang tao
ky sang » ky nang, ky dang, ky tang
ca dua » cay dua, ca cua, ca da
van ca » van cau, van cua, dan ca

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) OR (thu sach)) ky sang ma hoa. hieu van ca dua ban ((thanh vai) or (thanh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky sang ma hoa. hieu van ca dua ban ((thanh vai) OR (thanh hai)) cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky sang ma hoa. hieu van ca dua ban ((thanh vai) or (thanh hai)) cua tre*".