Frederick Engels books in order
9 books in the catalogue, about 23 hours of reading in all; the shortest takes 31 minutes and the longest 7 hours.
9 standalone books in the catalogue.
Standalone books
The Condition of the Working Class in England 6.6 h 
The Communist Manifesto 1.6 h 
The Civil War in France 1.7 h 
Socialism, Utopian and Scientific 1.7 h 
The Origin of the Family, Private Property and the State 4.0 h 
Wage-labour and Capital 53 min 
Ludwig Feuerbach and the Outcome of Classical German Philosophy 1.8 h Principles of Communism 31 min 
The German Ideology 3.9 h