History of "gay" being an umbrella term that included trans people at the time of the Stonewall riot:
https://www.google.com/books/edition/Trans_Bodies_Trans_Selves/gN5eEAAAQBAJ?hl=en&gbpv=1&pg=PA595&printsec=frontcover
https://archive.org/details/armyofexloversmy0000hoff/page/80/mode/2up?q=%22lesbian+and+gay%22&view=theater
https://archive.org/details/standbymeforgott0000down_l1k1/page/6/mode/2up?q=%22transgender%22&view=theater

"Anti-marriage equality org rebrands as anti-trans group"
https://www.starobserver.com.au/news/national-news/anti-marriage-equality-org-rebrands-as-anti-trans-group-binary-australia/173664

"Christian Right tips to fight transgender rights: separate the T from the LGB"
https://www.splcenter.org/hatewatch/2017/10/23/christian-right-tips-fight-transgender-rights-separate-t-lgb
https://en.wikipedia.org/wiki/Divide_and_rule

"A Cross-Cultural Investigation of Prejudice Against Transgender People"
https://journals.sagepub.com/doi/abs/10.1177/19485506241289638
"The current research offers a cross-cultural examination of transgender prejudice, with a particular focus on the role of gender. Analyses of a survey conducted in 23 countries (with N’s ranging from 485 to 1,098) representing both Western and non-Western societies ... anti-gay and anti-transgender prejudice were strongly related to each other across samples, and the denial of gender identity predicted anti-transgender prejudice over and above anti-gay prejudice."