%% You should probably cite draft-hares-i2nsf-merged-problem-use-cases instead of this I-D.
@techreport{dunbar-i2nsf-problem-statement-04,
    number =    {draft-dunbar-i2nsf-problem-statement-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-dunbar-i2nsf-problem-statement/04/},
    author =    {Linda Dunbar and Myo Zarny and Christian Jacquenet and Mohamed Boucadair and Shaibal Chakrabarty},
    title =     {{Interface to Network Security Functions (I2NSF) Problem Statement}},
    pagetotal = 20,
    year =      2015,
    month =     may,
    day =       21,
    abstract =  {This document describes the motivation and the problem statement for Interface to Network Security Functions (I2NSF).},
}