Between 1942 and 1945 a total of 74 pastors, 47 brothers, and 160 nuns were killed by the Japanese forces. For example, the Bishop of Maluku and West Papua Giovanni Aerts, along with eleven brothers and clergymen, was summarily executed (Gonggong 2012, p. 50). Some clergy, including Willekens, made use of the Vatican's diplomatic relations with Japan to claim diplomatic status, thus protecting themselves (Subanar 2005, p. 57). However, they planned for the possibility of Willieken's capture; in correspondence between Soegijapranata and Willekens, the two men agreed that Soegijapranata must remain free no matter the consequences (van Klinken 2003, p. 177). Gonggong, Anhar (2012). Mgr. Albertus Soegijapranata SJ: Antara Gereja dan Negara [Mgr. Albertus Soegijapranata SJ: Between the Church and the State] (in Indonesian) (Revised ed.). Jakarta: Grasindo. ISBN978-979-081-803-3. Subanar, G. Budi (2005). Menuju Gereja Mandiri: Sejarah Keuskupan Agung Semarang di Bawah Dua Uskup (1940–1981) [Towards an Independent Church: History of the Archdiocese of Semarang Under Two Archbishops (1940–1981)] (in Indonesian). Yogyakarta: Sanata Dharma University Press. ISBN978-978-979-210-8. van Klinken, Geert Arend (2003). Minorities, Modernity and the Emerging Nation: Christians in Indonesia, a Biographical Approach. Leiden: KITLV Press. ISBN978-90-6718-151-8.[permanent dead link]
Flinn 2010, pp. 576–577. Flinn, Frank K (2010). "Soegijapranata, Albert (Albertus Soegijapranata)". Encyclopedia of Catholicism. Encyclopedia of world religions; Facts on File library of religion and mythology. New York: Facts on File. pp. 576–577. ISBN978-0-8160-7565-2.