Polaroid Land Photography, pg. 228.
"Effects of development changes: Essentially none, since the print and negative develop to completion. A very slight decrease of the base-plus-fog density of the negative occured at 60 second. Insufficient development must be avoided, since it produces discoloraton of the negative when it is exposed to light."
"Tested optimum development time: 30 seconds at 70 deg. F"