Kull, A. Space Plasma Physics of Near-Earth Environment, MPI for Extraterrestrial Physics, Max Planck Society;
Kull, A. (1997). Self-reference and time according to Spencer-Brown. In H. Atmanspacher, & E. Ruhnau (Eds.), Time, Temporality, Now: Experiencing Time and Concepts of Time in an Interdisciplinary Perspective (pp. 71-79). Berlin, Germany: Springer.