http://lasto.com/blog/index_post_1583478000.htm
http://lasto.com/blog/index_post_1552374000.htm
http://lasto.com/i/blog/main/radio/151/book_qrp_linear_amplifier_by_SM0VPO.html
http://radiomaster.ru/articles/view/63/
http://lasto.com/i/blog/main/radio/151/book_compression_versus_limitation.pdf