Most of my thoughts are derived from audio books and courses that I listen on daily basis plus personal experience from user research on the products I am designing. In the company I work with we are doing weekly user interviews. It helps a lot to built good understanding for some universal principles that are valid across majority of users in majority of contexts.
Here are few examples of my sources in my library that help me draft my articles. Of course, on top of that I frequently do short desktop researches to see what else has been written. It helps me see how to add a different perspective not just repeat 1:1 the same stuff.
Hope this answers your question Karim. Thanks for taking the time to read the article and asking the questions! :)
