«Ronald Zollman». Archivado desde el original el 13 de noviembre de 2010. Consultado el 10 de junio de 2009. «Ronald Zollman was Musical Director of the National Orchestra of Belgium, a position he then held since 1993 with the Philharmonic Orchestra of UNAM in Mexico City.»
«General is Hailed as New Man in Mexico». Evening Independent. 27 de noviembre de 1913. Consultado el 10 de junio de 2009. «Huerta and his dictatorship is tottering today ... the government proposition to grant railroad rights to a Belgian syndicate, ...»
«Ronald Zollman». Archivado desde el original el 13 de noviembre de 2010. Consultado el 10 de junio de 2009. «Ronald Zollman was Musical Director of the National Orchestra of Belgium, a position he then held since 1993 with the Philharmonic Orchestra of UNAM in Mexico City.»