%% You should probably cite rfc3267 instead of this I-D.
@techreport{ietf-avt-rtp-amr-13,
    number =    {draft-ietf-avt-rtp-amr-13},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-ietf-avt-rtp-amr/13/},
    author =    {Qiaobing Xie and Johan Sjoberg and Ari Lakaniemi and Magnus Westerlund},
    title =     {{Real-Time Transport Protocol (RTP) Payload Format and File Storage Format for the Adaptive Multi-Rate (AMR) and Adaptive Multi-Rate Wideband (AMR-WB) Audio Codecs}},
    pagetotal = 49,
    year =      2002,
    month =     feb,
    day =       28,
    abstract =  {This document specifies a real-time transport protocol (RTP) payload format to be used for Adaptive Multi-Rate (AMR) and Adaptive Multi-Rate Wideband (AMR-WB) encoded speech signals. The payload format is designed to be able to interoperate with existing AMR and AMR-WB transport formats on non-IP networks. In addition, a file format is specified for transport of AMR and AMR-WB speech data in storage mode applications such as email. Two separate MIME type registrations are included, one for AMR and one for AMR-WB, specifying use of both the RTP payload format and the storage format. {[}STANDARDS-TRACK{]}},
}