Marxists.org page on Alienation http://www.marxists.org/subject/alienation/index.htm
Estranged Labour – Karl Marx (Economic and Philosophical Manuscripts of 1844) http://www.marxists.org/archive/marx/works/1844/manuscripts/labour.htm
Work and the Free Society – Anarchist Federation http://www.afed.org.uk/ace/work.html
From Man’s Alienation to Human Community – Internationalist Communist Group (Communism #6) http://libcom.org/library/from-mans-alienation-to-human-community-communism-6
An Anarchist Critique of Democracy http://www.againstallauthority.org/democracy.html (also available as audio here http://www.archive.org/details/AAnarchistCritiqueOfDemocracy )
Seeing sense in the age of stupid: Alienation, power and the case for social transformation – Solidarity Federation (Direct Action #47) http://www.direct-action.org.uk/docs/DA-SF-IWA-47.htm#33
Eugene Kamenka, The Ethical Foundations of Marxism: chapter 7, the Critique of Economics.
Capital Vol 1: the section on the fetishism of commodities http://www.marxists.org/archive/marx/works/1867-c1/ch01.htm#S4
Bertell Ollman, Alienation: part three, The theory of alienation.
Shlomo Avineri, The political and social theory of Marx: ‘Alienation and forms of property’
David McLellan, Selected Writings of Marx, chapter 8 and chapter 9