Dear EvolDir members, I received many replies to my inquiry about the the Muller 1942 last week on EvolDir (see below for original post). Thanks to all of you! Now I have what I was looking for. However, I found it important to give some more info back to you: It turns out that the full citation in something like: Hermann Joseph Muller, "Isolating mechanisms, evolution and temperature," in Temperature, Evolution, Development, ed. Theodosius Dobzhansky, vol. 6, Biological Symposia: A Series of Volumes Devoted to Current Symposia in the Field of Biology (Lancaster, PA: Jaques Cattell Press, 1942), 71-125. That is a book section (in a book of a whole series of books, 12 volumes), formally, and not a journal article. Hence there seems to be some error propagation with this citation, due to rough shortening of references in some journals. Just in case you would like to know ;-). Cheers, Robert ORIGINAL POST: Dear colleagues, When talking about Dobzhansky-Muller-Incompatibilities (DMIs) people usually cite one or two works of Dobzhansky and one of Muller, 1942. The reference is: MULLER HJ, 1942, Isolating mechanisms, evolution and temperature. Biol. Symp. 6:71-125. However, I just can't find this anywhere. Is there anyone who can help me trace it? The journal abbreviation is (to my taste) a bit ambiguous. Scopus, ISI, Google Scholar, or just Google itself fail to find it. All I get is articles citing the Muller (1942) over and over again (> 400 citations in Google scholar). Cheers, Robert robert.kraus@wur.nl