I. P. Christensen (Christensen, I. P.)

• 
  Instant Notes In Psychology
  by M. S. Halliday, I. P. Christensen, H. L. Wagner
  Softcover, Bios Scientific Pub Ltd, ISBN 1859960979 (1-85996-097-9)
• 
  Instant Notes Psychology
  by Hugh L. Wagner, M. S. Halliday, I. P. Christensen
  Softcover, Taylor & Francis, ISBN 0387915923 (0-387-91592-3)