Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
thanh vai » thanh van, thanh tai, thanh oai
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
dua ban » dia ban, cua ban, qua ban
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
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 ky ((sang ma) OR (nang 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 ky ((sang ma) OR (nang 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 ky ((sang ma) OR (nang ma)) hoa. hieu van ca dua ban ((thanh vai) or (thanh hai)) cua tre*".