https://ti.org/pdfs/Flyvbjerg02.pdf
Authors. Flyvbjerg, B., Holm, M. S. & Buhl, S
Venue. third-party PDF of Journal of the American Planning Association 68(3) , 279–292
How the Institute flags it
established 2 times frontier 1 time
This source carries more than one flag across the corpus. That is not an inconsistency to resolve: the same work can be established evidence for one claim and frontier evidence for another, and the flag belongs to the use rather than to the source.