%% You should probably cite draft-dreibholz-ipv4-flowlabel-39 instead of this revision.
@techreport{dreibholz-ipv4-flowlabel-21,
    number =    {draft-dreibholz-ipv4-flowlabel-21},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-dreibholz-ipv4-flowlabel/21/},
    author =    {Thomas Dreibholz},
    title =     {{An IPv4 Flowlabel Option}},
    pagetotal = 8,
    year =      2015,
    month =     jan,
    day =       12,
    abstract =  {This draft defines an IPv4 option containing a flowlabel that is compatible to IPv6. It is required for simplified usage of IntServ and interoperability with IPv6.},
}