%% You should probably cite draft-ietf-stox-groupchat instead of this I-D.
@techreport{saintandre-sip-xmpp-groupchat-04,
    number =    {draft-saintandre-sip-xmpp-groupchat-04},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-saintandre-sip-xmpp-groupchat/04/},
    author =    {Peter Saint-Andre and Saúl Ibarra Corretgé and Salvatore Loreto},
    title =     {{Interworking between the Session Initiation Protocol (SIP) and the Extensible Messaging and Presence Protocol (XMPP): Groupchat}},
    pagetotal = 32,
    year =      2013,
    month =     jun,
    day =       20,
    abstract =  {This document defines a bidirectional protocol mapping for the exchange of instant messages in the context of a multiparty chat session among users of the Session Initiation Protocol (SIP) and users of the Extensible Messaging and Presence Protocol (XMPP). Specifically, this document defines a mapping between the SIP-based Message Session Relay Protocol (MSRP) and the XMPP Multi-User Chat (MUC) extension.},
}