the eleusinian mysteries ...

a fairly random selection of articles that i googled ...

https://en.wikipedia.org/wiki/Eleusinian_Mysteries

https://thereaderwiki.com/en/Eleusinian_mysteries

https://medium.com/@mustaphahitani/eleusinian-mysteries-and-psychedelic-enlightenment-c9622cacfa6f

https://www.researchgate.net/publication/302998435_Ritual_Path_of_Initiation_into_the_Eleusinian_Mysteries

http://baringtheaegis.blogspot.com/2016/09/pat-ritual-announcement-eleusinian.html

https://femminaclassica.com/unraveling-the-eleusinian-mysteries/

etc, etc ..

https://maps.org/images/pdf/books/eleusis.pdf