#Discovery of the day:
Some of the most fundamental concepts in quantitative #Geography and #GIS were published in the #CATMOG series by the Institute of British Geographers (now part of the #RGS). Unfortunately, these publications are rarely available online, and an increasing number of libraries no longer carry this series. 
But thanks to Prof. Mark Green, almost all CATMOG publications are available on GitHub: https://github.com/qmrg/CATMOG/tree/Main
GitHubGitHub - qmrg/CATMOG: Preserved CATMOG (Concepts And Techniques in MOdern Geography) seriesPreserved CATMOG (Concepts And Techniques in MOdern Geography) series - qmrg/CATMOG