Perhaps you should try some spelling variations:
thanh van » thanh san, thanh toan, thanh phan
thanh tai » thanh hai, thanh toan, doanh tai
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cua triet, dua tren
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cac qua » cau qua, tac quan
van cac » van hac, van cau, van bac
sang ma » tang ma, nang ma, sang tao
ky sang » ky nang, ky dang, ky tang
cuu tre » cau tren, cau treo
ma hoi » mai hoi, xa hoi, ma hoa

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 hoi. hieu van cac qua quan ((thanh van) or (thanh tai)) ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky sang ma hoi. hieu van cac qua quan ((thanh van) OR (thanh tai)) ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky sang ma hoi. hieu van cac qua quan ((thanh van) or (thanh tai)) ((cua tre) or (cuu tre))*.