A new version is available
William C. Levengood, Physiologia Plantarum 92, no. 2 (1994): 356–363 — the principal peer-reviewed scientific publication of the BLT Research Team's residual-anomaly framework for crop circles. Levengood, a biophysicist, argued that crops in selected formations exhibit substantial node-elongation patterns consistent with brief intense heating, principally attributed to microwave radiation. The paper is the foundational peer-reviewed citation of the residual-anomaly research program; subsequent BLT work has substantially operated outside peer review. The paper remains substantively contested in broader mainstream-scientific framework.