%% You should probably cite draft-ietf-oauth-mtls instead of this I-D.
@techreport{campbell-oauth-mtls-01,
    number =    {draft-campbell-oauth-mtls-01},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-campbell-oauth-mtls/01/},
    author =    {Brian Campbell and John Bradley and Nat Sakimura and Torsten Lodderstedt},
    title =     {{Mutual TLS Profiles for OAuth Clients}},
    pagetotal = 10,
    year =      2017,
    month =     apr,
    day =       10,
    abstract =  {This document describes Transport Layer Security (TLS) mutual authentication using X.509 certificates as a mechanism for both OAuth client authentication to the token endpoint as well as for sender constrained access to OAuth protected resources.},
}