All the letters written by Giorgio La Pira to Pius XII have been published by the Fondazione La Pira in the volume
G. La Pira, Beatissimo Padre. Lettere a Pio XII, Andrea Riccardi and Isabella Piersanti eds, Milano, Mondadori 2004
In this section you can find quotations from the following seven letters:
§ The duty to defend the weak(1953)
§ I cannot remain silent (1953)
§ The meeting with the Soviet Ambassador (1954)
§ The copernican revolution in economy (1958)
§ Springtime for the Church and for nations (1958)
§ Algeria and the Arab world (1958)