Comparative analysis between osteosarcoma and Ewing's sarcoma: evaluation of the time from onset of signs and symptoms until diagnosis Análise comparativa entre osteossarcoma e sar... oleh Raquel Bezerra Guerra, Marcelo Duarte Tostes, Leandro da Costa Miranda, Olavo Pires de Camargo, André Mathias Baptista, Marcelo Tadeu Caiero, Telma Muria dos Santos Machado, Márcia Datz Abadi, Claudia Regina G.C.M Mendes de Oliveira, Renée Zon Filippi