%% You should probably cite rfc9272 instead of this I-D.
@techreport{ietf-bier-bar-ipa-04,
    number =    {draft-ietf-bier-bar-ipa-04},
    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-bier-bar-ipa/04/},
    author =    {Zhaohui (Jeffrey) Zhang and Tony Przygienda and Andrew Dolganow and Hooman Bidgoli and IJsbrand Wijnands and Arkadiy Gulko},
    title =     {{BIER Underlay Path Calculation Algorithm and Constraints}},
    pagetotal = 6,
    year =      2019,
    month =     may,
    day =       29,
    abstract =  {This document specifies general rules for interaction between the BAR (BIER Algorithm) and IPA (IGP Algorithm) fields defined in ISIS/ OSPFv2 Extensions for BIER. The semantics for the BAR and IPA fields (when both or any of them is non-zero) defined in this document updates the semantics defined in RFC8444/RFC8401.},
}