The Strip Cipher-The Spanish Official Method. - José Ramón Soler Fuensanta; Francisco Javier López-Brea Espiau (Cryptologia, 2007)

Spanish Enigma: A History of the Enigma in Spain. - José Ramón Soler Fuensanta; Francisco Javier López-Brea Espiau; Frode Weierud (Cryptologia, 2010)

A Cryptanalysis Service During the Spanish Civil War. - José Ramón Soler Fuensanta; Francisco Javier López-Brea Espiau; Diego Navarro Bonilla (Cryptologia, 2012)

Revealing Secrets in Two Wars: The Spanish Codebreakers at PC Bruno and PC Cadix. - José Ramón Soler Fuensanta; Francisco Javier López-Brea Espiau; Diego Navarro Bonilla (Cryptologia, 2013)