English: Sabine, Ritter, and Schmidt on the moon.
On page 97 of The Moon as Viewed by Lunar Orbiter (L. J. Kosofsky and Farouk El-Baz, NASA SP-200, 1970), a substantial portion of this image is shown with the following caption: "The unusual craters Sabine (right, 30 kilometers across) and Ritter, at the southwest edge of Mare Tranquilitatis. A possible volcanic origin of these craters is suggested by their relatively high floors, arcuate internal ridges, apparent lack of secondary craters, and close resemblance to each other. These characteristics resemble those of terrestrial calderas. Similar pairs exist on the moon's far side. Location: 1 (deg) 40' N, 19 (deg) 40' E. Framelet width: 12 kilometers."