Barbara C. Allen, Ph.D. (2001), Indiana University Bloomington, is Associate Professor of History at La Salle University, USA. She has published Alexander Shlyapnikov, 1885-1937: Life of an Old Bolshevik (Brill, 2015) and Leaflets of the Russian Revolution (Haymarket, 2018).

The Workers' Opposition in the Russian Communist Party: Documents, 1919-30 comprises translations of articles, speeches, theses, letters, and other documents pertaining to the activity of the Workers' Opposition group and its members during its existence and until 1930.