%% You should probably cite draft-ietf-avt-rtp-gsm-hr instead of this I-D.
@techreport{rocky-avt-rtp-gsm-hr-00,
    number =    {draft-rocky-avt-rtp-gsm-hr-00},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-rocky-avt-rtp-gsm-hr/00/},
    author =    {Rocky Wang and Ying Zhang},
    title =     {{Media Type Registration of GSM-HR payload Format}},
    pagetotal = 6,
    year =      2008,
    month =     jan,
    day =       24,
    abstract =  {This document registers a media type for the Real-time Transport protocol (RTP) payload format, which is used for the Group Special Mobile half-rate speech transcoding.},
}