Use of index cards by authors and researchers is pretty much legendary. From some earlier research I've done:

- Carl Linneaus, who largely invented the modern index card. https://www.sciencedaily.com/releases/2009/06/090616080137.h...

- Numerous library cataloguers, including Melvil Dewey.

- Vladimir Nabokov

- Garrett Hardin (of "Tragedy of the Commons" fame). I've seen his personal collection, which was extensive.

- Herb Caen, "three dot columnist" for the San Francisco. Chronicle.

- John McPhee, The Control of Nature and numerous other books. http://www.newyorker.com/magazine/2013/01/14/structure

I've written previously (discussion POIC, a similar model) here: https://ello.co/dredmorbius/post/u4dgr0tkxk4tk9npuvex5a

More on index card usage:

https://o.ello.co/https://www.theguardian.com/lifeandstyle/2...