BAUMANN, Kurt. Die blaue Blume am Wegesrand. Der Palmengarten, [S. l.], v. 73, n. 2, p. 136–140, 2009. DOI: 10.21248/palmengarten.96. Disponível em: https://ojs.ub.uni-frankfurt.de/Palmengarten/index.php/Palmengarten/article/view/96. Acesso em: 16 mai. 2024.