• Two approaches to systems theory : an analysis in the context of Ken Wilber's and Alfred North Whitehead's philosophical cosmologiesNäpinen, Leo6th International Whitehead Conference : the Importance of Process - System and Adventure : Universität Salzburg, July 3-6, 2006 : program: sections & abstracts2006 / p. 162
• Whitehead and the problem of the connection between the physical and the mathematicalNäpinen, Leo6th International Whitehead Conference : the Importance of Process - System and Adventure : Universität Salzburg, July 3-6, 2006 : program: sections & abstracts2006 / p. 12 https://www.researchgate.net/publication/320444536_Whitehead_and_the_problem_of_the_connection_between_the_physical_and_the_mathematical