Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA699185A
Inventor
C. Whitney David
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Field Enterprises Educational Corp
Original Assignee
Field Enterprises Educational Corp
Publication date
Application grantedgrantedCritical
Publication of CA699185ApublicationCriticalpatent/CA699185A/en