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
CA727872A
Inventor
Leathers Ward
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.)
EDUCATION METHODS COUNCIL
Original Assignee
EDUCATION METHODS COUNCIL
Publication date
Application grantedgrantedCritical
Publication of CA727872ApublicationCriticalpatent/CA727872A/en