C. A. Cunha,  "“Few, but Pure and Good Members, are Preferred to a Mass   Party.     The   Portuguese   Communist   Party´s Continued  Orthodoxy."", in Taking  Stock  of  Communist  and Post- Communist  Parties  in  Europe, Backes,  Uwe  and  Moreau, Patrick, Ed., Göttingen,  Germany, Vandenhoeck & Ruprecht, 2008, vol. 36, pp. 193-214