| Our Intelligent Companions, the Plants: Contains much information on various mind/plant type experiments throughout history. Some people mentioned include Cleve Backster and J. Chandra Bose. |
| Chapter Six- Cleve Backster's Laboratory: A chapter in a web-based book by psychologist Ingo Swann. Deals with a trip made by Swann to Backster's laboratory and chronicles the first-hand experiment he witnessed. |
| Dark Corner - Plants Feel: Offers information on how plants can read human minds. |
| Plant Articles by Judith Handelsman: A series of articles from various magazines. The second one has relevance primary perception discoveries, as it describes Handelsman's own experiences with the phenomenon. |
| Subtle Energy: An article in a web-based magazine by Paul von Ward Lightworks. Deals with Cleve Backster's mind-plant discoveries and the author's speculations about them. |
| Vignettes From the History of Plant Morphology: Articles about people, mostly Agnes Arber, who created unconventional theories about plant morphology. |
Classical
