Sources:
https://en.wikipedia.org/wiki/Invasion_of_Poland The invasion in general, good overview (english)
https://en.wikipedia.org/wiki/B%C5%82yskawica_radiostation overview of the station, included becuase it is one of the very freq english langauge sources (english)
https://web.archive.org/web/20051101233047/http://www.radio.com.pl/reportaz/mp3/audycje/2004-09-13.mp3 Interveiw with Zębik (polish)
https://www.polskieradio.pl/39/156/Artykul/905392 Article on the station (polish)
http://www.sppw1944.org/pamiec/repliki.html Article about a replica of the staion (polish)
https://muzhp.pl/pl/e/1224/pierwsza-audycja-radiostacji-armii-krajowej-blyskawica (polish)
https://web.archive.org/web/20170822014711/http://www.info-pc.home.pl/whatfor/baza/radiostacja_blyskawica.htm article (polish)
https://www.youtube.com/watch?v=1P8mFjQRIxA Over view of the  station (Polish)
https://www.youtube.com/watch?v=JRE5alpk2mA Videos (polish)
https://www.youtube.com/watch?v=y1SkwD6NPF8 Videos (polish)
www.powstaniewarszawskie.polskieradio.pl/ Page covering polish government radio booadcasts during the uprising