I can't find the exact studies, but some of them were on ACM

Articles/Threads:
https://medium.com/star-gazers/pythons-significant-whitespace-problems-995fd6c17
fd4
https://news.ycombinator.com/item?id=25591980
https://www.reddit.com/r/learnprogramming/comments/2z6wzc/what_are_the_downsides
_to_using_whitespace_to/
there's also a thread on programmerhumor, and some people have even mentioned
nim specifically:https://www.reddit.com/r/ProgrammerHumor/comments/49duud/a_nig
htmare_of_whitespace_sensitivity/ and another thread about the same thinghttps:
//www.reddit.com/r/programminghorror/comments/15sq3ge/code_in_abap_is_whitespace
sensitive/

whitespace sensitivity is good for SOME data structure formats (like yaml),
where there rarely ever is any global scope. However, in programming languages
where you have a global scope, it's rarely ever a good thing. The only real
benefit of it is enforcing code readability for absolute newbies to programming,
it does next to nothing for readability, as whitespace insensitive languages
already typically have some kind of widely used formatters (like prettier), such
that editors always handle the scopes correctly and the code is consistent in
style.