Timeline for all types of items produced by
McGraw-Hill Ryerson

Year	Items
1982	1
1983	2
1984	28
1985	2
1986	5
1987	1
1989	1

40 items with a valid date were considered for this timeline (80.00% of the total)
10 items with an invalid date.

Help us in our quest to find exact dates for:

198?: 10 items.