Krūmiņš, K., V. Pētersons, and V. Plociņš. “Features of Implementation of the Modified "Up-and-down" Method”. Elektronika Ir Elektrotechnika, vol. 93, no. 5, May 2009, pp. 51-54, https://eejournal.ktu.lt/index.php/elt/article/view/10180.