Reihe The Frontiers CollectionHans J. Pirner × The Unknown as an Engine for ScienceAn Essay on the Definite and the IndefiniteHans J. PirnerSpringer International PublishingSoftcover2016 The Unknown as an Engine for ScienceAn Essay on the Definite and the IndefiniteHans J. PirnerSpringer International PublishingHardcover2015 The Unknown as an Engine for ScienceAn Essay on the Definite and the IndefiniteHans J. PirnerSpringer International PublishingeBook2015