The texts in Volumes 28-37 represent the principal stages in the formation of Marx’s economic doctrine. Volumes 28 and 29 contain Marx’s Economic Manuscripts of 1857-58 (the first rough draft of Capital) and his work A Contribution to the Critique of Political Economy: Part One (1859). Volumes 30-34 comprise the Economic Manuscripts of 1861-63 (the second rough draft of Capital), volumes 35-37 contain volumes I, II and III of Capital. Volume 31 contains the continuation of Marx’s economic manuscript of 1861-63, its central part – “Theories of Surplus Value”. The beginning of the manuscript is published in Volume 30 and the rest appears in volumes 32-34.