A digitized abstract written by the author can be opened using publisher's DOI number. A digitized copy of the full text is available from the publisher. A paper offprint of the full text is at Fenwick Library, Box 31/15, C0016, SCRC, George Mason University Libraries.

Warfield's 1987 description for The Magical Number Three: "This paper reviews the Miller and Simon research on mental spans, introduces two new measures, and points out that if one considers a set of three items, their interactions in groups of two and a group of three, if significant, get added to the initial set of three to make a set of seven. For this reason, the magical number often should be thought of as three, instead of seven, because the three induce four more, except in those instances where there is no interaction among the set of three. The term "Proionic" is introduced to distinguish elements that do interact from those that do not."

John's comment about this paper as Rose remembers it when she questioned him for information to use in writing an annotation: "Oh yes, that paper, that is OK, but it is really just about one small portion of my work. I would not consider it one of the most significant or give it any special billing. Others were much better and more significant." (r.w. circa 2007)