Rismani, Sassan, and Dimas Widiantoro. “Relations Between Country R&D Expenses and Startup IPO in Europe: Empirical Research of Startup IPO Activities from 2005 to 2014”. International Entrepreneurship Review, vol. 2, no. 2, Oct. 2016, pp. 179-90, https://ier.uek.krakow.pl/pm/article/view/1122.