He is the author of ten books on the Holocaust, among them “Jewish Forced Labor under the Nazis. Economic Needs and Nazi Racial Aims”, with Cambridge University Press (paperback 2008), as well as over 60 academic articles and book chapters. He also coedited two books, one of them, the translated updated book “The Greater German Reich and the Jews. Nazi Persecution Policies in the Annexed Territories 1935-1945” was published in 2015 with Berghahn Books. Its original German edition received an award for most outstanding German studies in humanities and social sciences in 2012. In 2015, Gruner published on the discrimination against the indigenous population in post-colonial Bolivia the book „Parias de la Patria“. El mito de la liberación de los indígenas en la República de Bolivia 1825-1890”, in Spanish with Plural Editores, Bolivia. Gruner’s most recent book deals with the Persecution of the Jews in the Protectorate of Bohemia and Moravia and their responses 1939-45 (Wallstein, Goettingen, Germany, 2016). This book received the award for most outstanding German studies in humanities and social sciences in 2017.
He is a member of the International Academic Advisory board of the Center for the Research on the Holocaust in Germany at Yad Vashem’s International Institute for Holocaust Research, Jerusalem (since 2012), a member of the International Advisory Board of the Journal of Genocide Research (since 2010). He served as a member of the Yad Vashem 2014 International research Book prize committee. For the 2016 biannual international conference on the Holocaust “Lessons and Legacies”, he served as the co-chair of the academic program.