Copied after a painting by German artist, Otto Goldman (1844 - 1916). In the 1890s Gebbie & Company of Philadelphia, produced a steel engraving after Goldman's painting. It was titled, "Between Friends." It is likely Alten's oil was after the engraving.
Mathias Alten Exhibition
Sweeney, J. Gray "Mathias J. Alten (1871 -1938)," Exhibition Catalog (1979)
Sylvia Krissoff, "Exhibit Shows Range of GR Artist Alten's Work, " The Grand Rapids Press, July 30, 1991.
Smithsonian Institution Research Information System (SIRIS), "Alten, Mathias Joseph 1871-1938"