M. Schönkfinkel. Mathemati\-sche Annalen, (1924)English Translation appears in From Frege to Gödel: A Source
Book in Mathematical Logic, Harvard University Press, Cambridge, MA, 1967..
A. Markov. Izvistia Imperatorskoi Akademii Nauk (Bulletin de l'Académie
Impériale des Sciences de St.-Pétersbourg), (1913)English translation by Morris Halle, 1956..