Kalis, Harijs, and Ilmārs Kangro. “SIMPLE METHODS OF ENGINEERING CALCULATIONS FOR SOLVING TRANSFER PROBLEMS OF MULTI – SUBSTANCES IN HORIZONTAL LAYER”. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 1 (June 18, 2005): 40–47. Accessed November 27, 2024. https://journals.ru.lv/index.php/ETR/article/view/2132.