GRZEGORZ GRUNWALD; ADAM CIEĆKO; KAMIL KRASUSKI; RAFAŁ KAŹMIERCZAK. The GPS / EGNOS Positioning Quality in APV-1 and LPV-200 flight procedures. Communications - Scientific letters of the University of Zilina, v. 23, n. 2, p. E23-E34, 1 Apr. 2021.