The following pdf file contains all of the resized Project Blue Book documents below which are now housed on the NICAP site for security reasons.
The original over-sized docs from the Blue Book site are listed below:
July 12, 1952, Central Illinois
Wing Intelligence Section, Chanute AFB, Illinois
Inclosed are 9 statements concerning an unidentifeid object observed 12th July 1952 at various places in Central Illinois.
Source: Various military and civilian personnel
Page ID (PID) MAXW-PBB11-1461
Roll Description Maxwell Blue Book 11
Document Code N/A