Four Dimensional . . . 1 The Four-Dimensional Roller-Press by Bob Olsen “The Four-Dimensional Roller-Press” by Bob Olsen, Amazing Stories, June 1927.
Four Dimensional . . . 2 Four Dimensional Surgery by Bob Olsen “Four Dimensional Surgery” by Bob Olsen, Amazing Stories, February 1928.
Four Dimensional . . . 4 Four Dimensional Transit by Bob Olsen “Four Dimensional Transit” by Bob Olsen, Amazing Stories Quarterly, Fall 1928.
Four Dimensional . . . 3 Four Dimensional Robberies by Bob Olsen “Four Dimensional Robberies” by Bob Olsen, Amazing Stories, May 1928.
Four Dimensional . . . 5 The Man Who Annexed the Moon by Bob Olsen “The Man Who Annexed the Moon” by Bob Olsen, Amazing Stories, February 1931.
Four Dimensional . . . 6 The Four Dimensional Escape by Bob Olsen “The Four Dimensional Escape” by Bob Olsen, Amazing Stories, December 1933.
Four Dimensional . . . 7 The Four Dimensional Auto-Parker by Bob Olsen “The Four Dimensional Auto-Parker” by Bob Olsen, Amazing Stories, July 1934.