%% You should probably cite rfc8967 instead of this I-D.
@techreport{ietf-babel-hmac-06,
    number =    {draft-ietf-babel-hmac-06},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-ietf-babel-hmac/06/},
    author =    {Clara Do and Weronika Kolodziejak and Juliusz Chroboczek},
    title =     {{HMAC authentication for the Babel routing protocol}},
    pagetotal = 19,
    year =      ** No value found for 'doc.pub_date.year' **,
    month =     ** No value found for 'doc.pub_date' **,
    day =       ** No value found for 'doc.pub_date.day' **,
    abstract =  {This document describes a cryptographic authentication mechanism for the Babel routing protocol that has provisions for replay avoidance. This document updates RFC 6126bis and obsoletes RFC 7298.},
}