Popper, K. [. (1999). All life is problem solving. Routledge.
Citazione stile Chigago Style (17a edizione)Popper, Karl [Raimund. All Life Is Problem Solving. London: Routledge, 1999.
Citatione MLA (9a ed.)Popper, Karl [Raimund. All Life Is Problem Solving. Routledge, 1999.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.