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“Terrorist threat assessment 2019-2021” (ICCT: The Hague, 2022).
“Normalisation, party politics and vigilantism: why the next terrorist wave will not be right-wing extremist” (ICCT: The Hague, 2020).
“Linking perpetrator characteristics to jihadist modus operandi: an exploratory study”, Suzanne C. Knittel, Zachary J. Goldberg (eds.), The Routledge International Handbook of Perpetrator Studies (Routledge, 2019): 95-106.
“The more things change, the more they stay the same: the post-Caliphate jihadist modus operandi in Europe”, Serafettin Paktas, Johan Leman (eds.), Militant jihadism: today and tomorrow (Leuven University Press, 2019): 123-140.
“The fate of the perpetrator in the jihadist modus operandi: suicide attacks and non-suicide attacks in the West, 2004-2017” (ICCT: The Hague, 2017).
“De aantrekkingskracht van de aanslag: negen behoeftes waar deelname aan terroristische activiteiten in voorziet”, Wim Hardyns, Willy Bruggeman (eds.), Radicalisering en terrorisme: van theorie naar praktijk (Maklu, 2016): 51-70.
“The case for tailored interventions in the preventive approach: lessons from countering jihadism in the Netherlands and the UK”, Siddik Ekici, Hüseyin Akdoğan, Eman Ragab, Ahmet Ekici and Richard Warnes (eds.), Countering terrorist recruitment in the context of armed counter-terrorism operations (IOS Press, 2016): 146-155.
“Towards a full understanding of terrorist leadership elimination: a research agenda”, Marko Milosevic and Kacper Rekawek (eds.), Perseverance of terrorism: focus on leaders (IOS Press, 2014): 38-49.
“The lengths terrorists go to: perpetrator characteristics and the complexity of jihadist terrorist attacks in Europe, 2004-2011”, Behavioral Sciences of Terrorism and Political Aggression, vol. 6, no. 1 (2014): 58-80.
“Terrorist leadership elimination: when to do it”, Polish Quarterly of International Affairs, vol. 22, no. 1 (2013): 106-115.
“Law enforcement as politics by other means: lessons from countering revolutionary terrorism”, Police Practice and Research, vol. 14, no. 5 (2013): 428-441.
“Need for empirical research on the effectiveness of counterterrorism strategies”, F. Shanty (ed.), Counterterrorism: from the Cold War to the War on Terror – vol. 1: combating modern terrorism (1968-2011) (Greenwood Publishing Group: Westport, 2012): 577-581, with R. de Wijk.
“Netherlands”, F. Shanty (ed.), Counterterrorism: from the Cold War to the War on Terror – vol. 1: combating modern terrorism (1968-2011) (Greenwood Publishing Group: Westport, 2012): 139-143, with R. de Wijk.
“Break it down: an alternative approach to measuring effectiveness in counterterrorism”, Journal of Applied Security Research, vol. 6, no. 3 (2011): 357-371.
“Mapping counterterrorism: a categorisation of policies and the promise of empirically based, systematic comparisons”, Critical Studies on Terrorism, vol. 3, no. 2 (2010): 227-241.