Clockwise:
1983 The 200th Anniversary of the Birth of Poet N.F.S. Grundtvig
Issued Nov. 3, 1983
Perf. 12¾ | Design: Jane Muus | Issued in sheets of 50 | Engraving: Czeslaw Slania | No watermark
747 A232 2.5Kr Brown red | N.F.S. Grundtvig, Poet
1987 The 100th Anniversary of the Danish Cooperative Bacon Factories
Issued Jun. 18, 1987
Perf. 12¾ | Design: Bente Olesen Nystrom | Issued in sheets of 50 | Engraving: Arne Kühlmann | No watermark
841 A289 3.80Kr Multicolored | Domesticated pigs (Sus scrofa domesticus)
1992 EUROPA Stamps – The 500th Anniversary of the Discovery of America
Issued May 7, 1992
Perf. 12¾ | Design: Niels Winkel | Issued in sheets of 50 | Litho. & Engr. | Engraving: Martin Mörch | No watermark
959 A342 3.50Kr Brown & green | Potato plant* (Solanum tuberosum)
*I’m not 100% sure why the potato is significant to this anniversary. The first permanent potato patches on US soil were established in 1719 near Londonderry, New Hampshire by Scotch-Irish immigrants.
1989 Nordic Cooperation Issue
Issued Apr. 20, 1989
Perf. 12¾ | Design: Birgit Forchhammer | Issued in sheets of 50 | Litho. & Engr. | Engraving: Arne Kühlmann | No Watermark
868 A312 3.20Kr Multicolored | Woman from Valby
1984 “Plant a Tree” Campaign
Issued Jan. 26, 1984
Perf. 12¾ | Design: Tage Stentoft | Issued in sheets of 50 | Litho. & Engr.|Engraving: Arne Kühlmann | No Watermark
749 A234 2.70Kr Red & green | Shovel and sapling
1982 The 500th Anniversary of the University Library
Issued Nov. 4, 1982
Perf. 12¾ | Design: Lisbeth Gasparski | Issued in sheets of 50 |Engraving: Arne Kühlmann | No Watermark
731 A221 2.70Kr Multicolored | Library Seal
[Sources: stampworld.com, Scott 2012 Standard Postage Stamp Catalogue, Vol. 2]