It seems a solid resource. If this is the one the quote is taken from, it is fairly recent - 1994. This was published after the work by Sparks you quote.
Philip Schaff (January 1, 1819 – October 20, 1893)
127 posted on 05/17/2015 5:25:23 PM PDT by newberger
(Put not your trust in princes, in sons of men in whom there is no salvation.)