+% Some ideas to locate the article:
+% * https://pubs.acs.org/action/doSearch?text1=Ralph+E.+Dunbar
+% * https://pubs.acs.org/doi/10.1021/ed035p161.2
+% * https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1949-8594.1936.tb11120.x
+% * https://onlinelibrary.wiley.com/doi/full/10.1111/j.1949-8594.1938.tb14456.x