- The Sentient Cell: The Cellular Foundations of Consciousness
- Communication in Plants: Neuronal Aspects of Plant Life
- Secretions and Exudates in Biological Systems
- Structure and Function of Roots: Proceedings of the Fourth International Symposium on Structure and Function of Roots, June 20-26, 1993, Stará Lesná, Slovakia
- Signaling and Communication in Plant Symbiosis