* "The New Gay Man" (1995): This book was a groundbreaking exploration of gay men's lives in the wake of the AIDS epidemic. It explored topics like sexuality, relationships, identity, and the impact of HIV/AIDS.
* "Making History: The Fight for Gay and Lesbian Rights" (1999): This book examines the history of the gay rights movement in the United States, covering key figures and events.
Marcus has also contributed to various publications including The Advocate, the New York Times, and the Los Angeles Times.
It's worth noting that while these are his most prominent works, he has also written other books and articles on related topics. You can find more information about his writings on his website or through online booksellers.