%% You should probably cite rfc8685 instead of this I-D.
@techreport{ietf-pce-hierarchy-extensions-05,
    number =    {draft-ietf-pce-hierarchy-extensions-05},
    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-pce-hierarchy-extensions/05/},
    author =    {Fatai Zhang and Quintin Zhao and Oscar Gonzalez de Dios and Ramon Casellas and Daniel King},
    title =     {{Extensions to Path Computation Element Communication Protocol (PCEP) for Hierarchical Path Computation Elements (PCE)}},
    pagetotal = 30,
    year =      2018,
    month =     jul,
    day =       16,
    abstract =  {The Hierarchical Path Computation Element (H-PCE) architecture RFC 6805, provides a mechanism to allow the optimum sequence of domains to be selected, and the optimum end-to-end path to be derived through the use of a hierarchical relationship between domains. This document defines the Path Computation Element Protocol (PCEP) extensions for the purpose of implementing necessary Hierarchical PCE procedures and protocol extensions.},
}