1. The 57th BALTIC CONTEST (2021) - http://www.lrsf.lt/en/balticcontestrules/
Period: from 2100z May 22, 2021 till 0200z May 23, 2021 UTC
Special trophies: (trophy/donor)
Baltic States QRP (less than 5W output) - Lithuanian Amateur Radio Society
2. Andromeda SDR -Apache Labs - http://www.nerfd.net/2021/05/07/andromeda-sdr-apache-labs/
3. Черговий випуск 432 and Above EME Newsletters (April 2021 VOL 51 #3) - http://www.nitehawk.com/rasmit/NLD/eme2104.pdf
4. Digital Calling Frequencies - https://projects.vk6flab.com/projects/all-modes-all-bands-all-countries/digital-calling-frequencies
5. FT8 Chat - https://dxcenter.com/FT8Chat/