Complex sentence: Przeczek edited and contributed to Polish magazines for children ("Jutrzenka ","Ogniwo ") and wrote several textbooks for Polish schools in Czechoslovakia; and was also a member of Polish editorial staff of the"Profil" publishing house in Ostrava.
Split into simpler sentences: Przeczek edited and contributed to Polish magazines for children "Jutrzenka" and "Ogniwo", and wrote several textbooks for Polish schools in Czechoslovakia. He was also a member of Polish editorial staff of the "Profil" publishing house in Ostrava.