[PROJ] "eck_greif" projection, "libproject"?

[Mike Taves]

On Thu, 5 Mar 2020 at 10:49, Nyall Dawson <nyall.dawson at gmail.com> wrote:
> Does anyone know what the "+proj=eck_greif" mentioned in section 7.2.1
> of http://priede.bf.lu.lv/ftp/pub/TIS/bibliotekas/PROJ.4/libproj4_manual.pdf
> refers to? I can't find any reference to this in master proj code base

See https://en.wikipedia.org/wiki/Eckert-Greifendorff_projection