Overview
Genre
| 2# | 11 | Overview | Omit | Problems |
| 3# | 11 | Overview | Omit | Problems |
| n# | 11 | Overview | Omit | Problems |
| Fairies | 4 | Overview | Omit | Problems |
| s# | 3 | Overview | Omit | Problems |
| Retro | 1 | Overview | Omit | Problems |
| h# | 1 | Overview | Omit | Problems |
Authors
| Grupen, Claus | 18 | Overview | Omit | Problems |
| Armeni, Alberto | 3 | Overview | Omit | Problems |
| Howard, David M. | 3 | Overview | Omit | Problems |
| Fulpius, Jaques | 2 | Overview | Omit | Problems |
| Gool, Johann Christoffel | 1 | Overview | Omit | Problems |
| Pancaldo, Julio Alberto | 1 | Overview | Omit | Problems |
| Vitale, Luigi | 1 | Overview | Omit | Problems |
| Thornton, Mark | 1 | Overview | Omit | Problems |
| Notaro, Rosario | 1 | Overview | Omit | Problems |
| Markowzij, Wassyl J. | 1 | Overview | Omit | Problems |
| Stockford, Dom C. | 1 | Overview | Omit | Problems |
| Butcher, F. G. | 1 | Overview | Omit | Problems |
| Zucal, Hector Guillermo | 1 | Overview | Omit | Problems |
| Bernard, Henry D'Oyly | 1 | Overview | Omit | Problems |
| White, J. J. R. | 1 | Overview | Omit | Problems |
| Willmott, Arthur | 1 | Overview | Omit | Problems |
| Lindgren, Bo | 1 | Overview | Omit | Problems |
| Wachenhusen, Christian | 1 | Overview | Omit | Problems |
| Morse, Christopher Jeremy | 1 | Overview | Omit | Problems |
| Mansfield, Comins | 1 | Overview | Omit | Problems |
| Groeneveld, Cornelis | 1 | Overview | Omit | Problems |
| Swindley, Cyril P. | 1 | Overview | Omit | Problems |
Sources
| Problem Observer | 44 | Overview | Omit | Problems |
| Die Schwalbe | 3 | Overview | Omit | Problems |
| feenschach | 2 | Overview | Omit | Problems |
| Schach-Echo | 2 | Overview | Omit | Problems |
| Springaren | 2 | Overview | Omit | Problems |
| The Problemist | 2 | Overview | Omit | Problems |
| Tim Krabbé's Website | 1 | Overview | Omit | Problems |
| U.S. Problem Bulletin | 1 | Overview | Omit | Problems |
| Tehtäväniekka | 1 | Overview | Omit | Problems |
| The Chess Amateur | 1 | Overview | Omit | Problems |
| Selbstmatt-Miniaturen Reflexmatt-Miniaturen | 1 | Overview | Omit | Problems |
| Problem-Observer | 1 | Overview | Omit | Problems |
| All Change Here! | 1 | Overview | Omit | Problems |
| Beispiele zur Ideengeschichte des Schachproblems | 1 | Overview | Omit | Problems |
| British Chess Federation | 1 | Overview | Omit | Problems |
| FIDE Album 1914-1944/I | 1 | Overview | Omit | Problems |
| FIDE Album 1959-1961 | 1 | Overview | Omit | Problems |
| FIDE Album 1986-1988 | 1 | Overview | Omit | Problems |
| Mat Plus | 1 | Overview | Omit | Problems |
| Phenix | 1 | Overview | Omit | Problems |
| Probleemblad | 1 | Overview | Omit | Problems |
Keywords
Computer tested
| not C+ | 29 | Overview | Omit | Problems |
| C+ | 13 | Overview | Omit | Problems |
Cooked
| not cooked | 41 | Overview | Omit | Problems |
| cooked | 1 | Overview | Omit | Problems |
https://pdb.dieschwalbe.de/overview.jsp?expression=COMMENTDATE%3E%3D20200919+AND+NOT+K%3D%27Hilfsr%C3%BCckz%C3%BCger%27+AND+NOT+K%3D%27Batterieaufbau%27+AND+S%3D%27Problem+Observer%27