%% You should probably cite draft-ietf-avt-rtcpssm instead of this I-D.
@techreport{chesterfield-avt-rtcpssm-02,
    number =    {draft-chesterfield-avt-rtcpssm-02},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-chesterfield-avt-rtcpssm/02/},
    author =    {Julian Chesterfield and Joerg Ott},
    title =     {{RTCP Extension for Source Specific Multicast Sessions with Unicast RTCP feedback}},
    pagetotal = 18,
    year =      2001,
    month =     nov,
    day =       30,
    abstract =  {This document specifies a modification to the Real-time Transport Control Protocol to enable the operation of RTP/RTCP with unicast RTCP feedback in Single Source multicast sessions such as Source Specific Multicast (SSM) Communication where the traditional model of Any Source Multicast (ASM) group communication of many to many is not possible and for any group communication which might benefit from a sender controlled summarised reporting mechanism. This specification extends {[}1{]}, section 6 which defines the RTP session group control channel.},
}