The Church: Selected Writings of Arthur Carl Piepkorn was originally published in 1993 by American Lutheran Publicity Bureau (ALPB). ISBN-10 096331422X, ISBN-13: 978-0963314222. The book was edited by Michael P. Plekon and William S. Wiecher, and includes an afterword by Richard John Neuhaus. ALPB republished “The Church” in 2007 with the designation “Volume 1.” This work is referred to as “Volume 1: The Church” on this website.
The Sacred Scriptures and the Lutheran Confessions was published in 2007 as “Volume 2 of the Selected Writings of Arthur Carl Piepkorn” by CEC Press, edited by Philip J. Secker (the Director of the Arthur Carl Piepkorn Center for Evangelical Catholicity” and operator of this website). This work is referred to as “Vol: 2” on this website.
The navigation menu at the top of this website provides a link to Volume 1: The Church with further details on that work. the Volume 2 option contains a number of sub-pages related that Volume 2, including information on how to order it and what libraries are known to have copies.