I'm writing a manuscript on the R client (https://github.com/ropensci/rgbif/ ) I maintain for the GBIF API. I may also include some stuff about the Python client (https://github.com/sckott/pygbif ) as well. 

If you have any feedback, please do chime in soon, either on the Github repo at https://github.com/sckott/msrgbif, or on our discussion forum at https://discuss.ropensci.org/t/feedback-on-rgbif-manuscript/290 

Best, Scott