T. Gries and M. Redlin, “Pirates – The Young and the Jobless: The Effect of Youth Bulges and Youth Labor Market Integration on Maritime Piracy,”10.1080/10242694.2017.1333797__Defence and Peace Economics, vol. 30, no. 3, pp. 309–323, 2019, doi:10.1080/10242694.2017.1333797 .

K. De Jaegher and B. Hoyer, “Collective action and the common enemy effect,” Defence and Peace Economics, vol. 27, no. 5, pp. 644–664, 2014.