[Marxism] Source of Rosa Luxemburg Quote?

[Vince Garton]

The original German quote seems to be slightly different, 'Wie Las­salle 
sagte, ist und bleibt die revo­lu­tio­närste Tat, immer ›das laut zu 
sagen, was ist‹.' (literally 'As Lassalle said, it is and remains the 
most revolutionary act to always "say loudly what is"').I've found two 
places which trace it to the 1906 essay 'In revolutionärer Stunde: Was 
weiter?', in Gesammelte Werke, vol. 2, p. 36, but I have no means of 
checking that at the moment. Hope that's of some help at any rate.

Yours

Vincent