Michael Lebowitz is professor emeritus of economics at Simon Fraser University in Vancouver, Canada, and the author of several books including The Socialist Imperative, The Contradictions of “Real Socialism,” and The Socialist Alternative. He was Director, Program in Transformative Practice and Human Development, Centro Internacional Miranda, in Caracas, Venezuela, from 2006-11.
A regular study of Marx's Capital (it misses some essential concepts but nonetheless it gets through).
The critique to other schools (neoclassics, neoricardians and marxist analytics) is pretty good.
The study of the dialectic method is the best part: it really shows the 'secrets' of Hegel in Marx's own method.
The problem with this book is it's ambition, and therefore, it's extention: separate studies would've been much better rather than a collage of multiple topics.