Gilbert, Barrie: 'Design considerations for BJT active mixers' (Materials, Circuits and Devices, 1996), 'Low-power HF Microelectronics: a unified approach', Chap. 23, pp. 837-928, DOI: 10.1049/PBCS008E_ch23
IET Digital Library, https://digital-library.theiet.org/;jsessionid=yc4lgqivbvid.x-iet-live-01content/books/10.1049/pbcs008e_ch23