In addition, a high-level overview of the methodolgy is available in Global Human Modification: Mapping Current Condition of Landscapes and in the following peer reviewed article:
Kennedy, C. M., J. R. Oakleaf, D. M. Theobald, S. Baruch-Mordo, and J. Kiesecker. 2019. Managing the middle: A shift in conservation priorities based on the global human modification gradient. Global Change Biology. 25:811–826. https://doi.org/10.1111/gcb.14549.