%% You should probably cite draft-ietf-tokbind-negotiation instead of this I-D.
@techreport{popov-tokbind-negotiation-00,
    number =    {draft-popov-tokbind-negotiation-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-popov-tokbind-negotiation/00/},
    author =    {Andrei Popov and Magnus Nyström and Dirk Balfanz and Adam Langley},
    title =     {{Transport Layer Security (TLS) Extension for Token Binding Protocol Negotiation}},
    pagetotal = 7,
    year =      2015,
    month =     may,
    day =       29,
    abstract =  {This document specifies a Transport Layer Security (TLS) {[}RFC5246{]} extension for the negotiation of Token Binding protocol {[}TBPROTO{]} version and key parameters.},
}