References:

https://stpaulcenter.com/posts/where-do-we-find-church-teaching-on-the-real-presence

Catechism Part Two  In Brief:

https://www.vatican.va/content/catechism/en/part_two/section_two/chapter_one/article_3/in_brief.html

Catholic Answers: https://www.catholic.com/qa/do-any-other-faiths-believe-in-transubstantiation

Orthodox Church in America: Holy Eucharist

https://www.oca.org/orthodoxy/the-orthodox-faith/worship/the-sacraments/holy-eucharist

https://www.detroitcatholic.com/voices/luther-s-defense-of-the-real-presence-in-the-eucharist

Greek Orthodox Archdiocese of America: The Holy Eucharist

https://www.goarch.org/-/the-holy-eucharist

https://www.copticchurch.net/introduction-to-the-coptic-church/sacraments/4_eucharist