Stankūnas, Jonas, and Vaidotas Kondroška. “Airspace Modelling at a Macroscopic Level”. Mokslas – Lietuvos ateitis / Science – Future of Lithuania 1, no. 6 (April 15, 2011): 115-119. Accessed September 20, 2021. https://journals.vgtu.lt/index.php/MLA/article/view/10641.