Historical clue formulations

• Philosopher Friedrich — 2023-11-03
• Marx's co-author for "The Communist Manifesto" — 2023-03-05
• Marx's collaborator on "The Communist Manifesto" — 2022-01-17
• "Socialism: Utopian and Scientific" writer, 1880 — 2021-08-29
• Author of 1884's "The Origin of the Family, Private Property and the State" — 2021-02-06
• Author of "The Condition of the Working Class in England," 1845 — 2020-01-25
• Marx's collaborator on "The Communist Manifesto" — 2019-07-08
• Marx collaborator — 2017-09-28
• Communist Friedrich — 2011-12-29
• Marx's collaborator on "The Communist Manifesto" — 2007-12-02
• Marx collaborator — 2006-12-14
• Marx collaborator — 2003-10-14
• Manifesto writer of 1848 — 2002-01-04
• "Anti-Dühring" author — 2001-09-29
• "Communist Manifesto" co-author — 2001-04-25
• Marx collaborator — 1996-06-02
• "Communist Manifesto" coauthor — 1994-05-14