The following references provide additional information to help you design efficient cooling circuits.
-  Gastrow, Hans Injection Molds: 108 Proven Designs Edited by K. Stoeckhert. Hanser Publishers, Munich Vienna New York 1993.
-  Menges, G. and Mohren, P. How To Make Injection Molds, 2nd Edition Hanser Publishers, Munich Vienna New York 1992.
-  Douglas M. Bryce. Plastic Injection Molding: Mold Design and Construction Fundamentals Society of Mechanical Engineers 1998.