Analysis of "the Real Author" of Communist Manifesto

Opinions on who is the real author of Communist vary as follows: 1.it's cooperative work of Marx and Engels;2.Marx wrote it alone;3.Engles took up the major work.In fact,the basic difference between Communist Manifesto and its original Tenet of Communist is that the former skillfully applies and expounds historical materialism.Therefore the founder of historical materialism and the real author of Communist Manifesto should be the same,i.e Marx and Engles are joint authors.The analysis of The German Ideology,which publicized the outlook on historical materialism for the first time,will be helpful to answer the question of who is the real author of Communist Manifesto.