So you find that a rightwing and left wing unreliable source agree and assume they must both be correct  There has been considerable study of Marx and there is no reason that we need to use popular books as sources  The only reason one would use them is that they contain claims that have not been accepted by mainstream historians  Also they lead us into discussions about what really happened which is a misuse of other editors time  We have an unsubstantiated claim by Jenny Marx made years after the event that her husband provided money for workers to buy weapons  We do not by the way have any reliable sources that these workers obtained or used weapons in Belgium in   Reliable sources state that the French government supplied unemployed Belgian workers with weapons in Paris and these workers then returned to Belgium in an attempt to overthrow the government  We know that Marx was arrested on suspicion of carrying arms and was ejected from the country but in fact the accusation was false  The types of additional sources that Martintg has provided are unreliable  Boris Nicolaevsky for example was a communist activist writing in  not a mainstream historian  Wheen and Muravchick are neoconservatives writing outside the academic mainstream  We just do not know what Marx did with the  francs he received