International Electrotechnical Commission (IEC), Institute of Electrical and Electronics Engineers (IEEE),
IEC/IEEE 62704-4:2020: 1-104, ISBN 978-2-8-3228535-0
2020 XXXIIIrd General Assembly and Scientific Symposium of the International Union of Radio Science, Rome, Italy. IEEE: pp. 1-4; ISBN 978-1-7281-5690-3