E. Štāls, A. Zigmunde, and R. Lapsa, “The Contribution of Riga Polytechnicum / Riga Polytechnic Institute Graduates (1875–1916) to Maritime Affairs in the 19th and 20th Centuries”, HESIHE, vol. 9, pp. 8–20, Dec. 2025, doi: 10.7250/HESIHE.2025.002.