%% You should probably cite draft-ietf-ecrit-psap-callback instead of this I-D.
@techreport{schulzrinne-ecrit-psap-callback-03,
    number =    {draft-schulzrinne-ecrit-psap-callback-03},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-schulzrinne-ecrit-psap-callback/03/},
    author =    {Henning Schulzrinne and Hannes Tschofenig and Milan Patel},
    title =     {{Public Safety Answering Point (PSAP) Callbacks}},
    pagetotal = 19,
    year =      2010,
    month =     mar,
    day =       8,
    abstract =  {After an emergency call is completed (either prematurely terminated by the emergency caller or normally by the call-taker) it is possible that the call-taker feels the need for further communication or for a clarification. For example, the call may have been dropped by accident without the call-taker having sufficient information about the current situation of a wounded person. A call-taker may trigger a callback towards the emergency caller using the contact information provided with the initial emergency call. This callback could, under certain circumstances, then be treated like any other call and as a consequence, it may get blocked by authorization policies or may get forwarded to an answering machine. The IETF emergency services architecture addresses callbacks in a limited fashion and thereby covers a couple of scenarios. This document discusses some shortcomings and raises the question whether additional solution techniques are needed.},
}