The Rev. Patrick Howell is vice president for mission and ministry at the School of Theology and Ministry at Seattle University. He co-edited the book Empowering Authority: The Charisms of Episcopacy and Primacy in the Church Today. He has frequently written about Pope Benedict XVI for the Seattle Times.

Sandra Yocum is chair of religious studies at the University of Dayton who specializes in the history of theology, which is Benedict’s forte.

Mark Ellingsen is an associate professor at the Interdenominational Theological Center in Atlanta. He is the author of the article “Joseph Ratzinger: How Conservative is Benedict XVI?” in the October 2005 issue of Theology Today.

The Vatican Web site lists all of Benedict’s activities, meetings and writings.

Greg Tobin is senior adviser for communications at Seton Hall University in New Jersey and author of Holy Father: Pope Benedict XVI: Pontiff for a New Era.

The Rev. Thomas G. Guarino is a professor of systematic theology at Seton Hall University in New Jersey. He has written on the theological vision of Joseph Ratzinger.

The National Catholic Reporter has a June 22, 2009, podcast and summary of a story, “Jesuit sees convergence of U.S., Vatican policies,” featuring an interview with the Rev. Thomas Reese about relations between the Vatican and the Obama administration.

Read a June 22, 2009, National Catholic Reporter story, “Progressive Catholics at home in Obama administration.”

Read a June 22, 2009, analysis of the encyclical’s themes, “Economic encyclical expands on church’s ‘best kept secret’,” by National Catholic Reporter columnist John L. Allen Jr.