http://www.hymntime.com/tch/bio/p/o/l/a/polack_wg.htm

https://onlinebooks.library.upenn.edu/webbin/book/lookupname?key=Polack%2C%20W.%20G.%20(William%20Gustave)%2C%201890-1950

https://www.librarything.com/author/polackwilliamgustave

https://hymnary.org/person/Polack_WG

https://www.findagrave.com/memorial/116656622/william-gustave-polack

https://media.ctsfw.edu/Person/Details/455