 A small number of scientists (physicist Eltjo Haselhoff, the late biophysicist William Levengood) have found differences between the crops inside the circles and outside them, citing this as evidence they were not man-made.Levengood published papers in journal "Physiologia Plantarum" in 1994 and 1999.In his 1994 paper he found that certain deformities in the grain inside the circles were correlated to the position of the grain inside the circle.