H. KALIS and I. KANGRO, Effective Finite Difference and Conservative Averaging Methods for Solving Problems of Mathematical Physics. Rēzekne, Latvia: Rēzeknes Tehnoloģiju akadēmija, 2021. Accessed: Jan. 26, 2025. [Online]. Available: https://books.rta.lv/index.php/RTA/catalog/book/24