ZVIRGZDIŅŠ, Indulis. Pedagogical and Political Activity of Pēteris Sauleskalns (1876–1975), a Graduate (1908) of Riga Polytechnic Institute. History of Engineering Sciences and Institutions of Higher Education, Riga, Latvia, v. 6, p. 56–72, 2022. DOI: 10.7250/HESIHE.2022.004. Disponível em: https://hesihe-journals.rtu.lv/hesihe/article/view/HESIHE.2022.004.. Acesso em: 6 mar. 2026.