1. 1 Watt QRP Power Transmitter - http://electronics-diy.com/1-watt-qrp-power-transmitter.php
2. Презентація Quad Band Inverted V maybe 15M too? - https://slideplayer.com/slide/16949584/
3. CQ Amateur Radio №4 - http://www.radiofiles.ru/news/cq_amateur_radio_4_2021/2021-04-02-6125
** Ham Radio For Dummies 4-th Edition - http://www.radiofiles.ru/news/ham_radio_for_dummies_4_th_edition/2021-04-01-6130
4. Умови першого голландського PACCDIGI CONTEST - https://www.contestcalendar.com/contestcal_qrp.html
starts: april 17 at 12:00 utc
ends: april 17 at 23:59 utc
5. PCB Project (велика добірка саморобних проектів) - https://www.pcbway.com/project/shareproject/