H. Forwald: An experimental study suggesting a relationship between psychokinesis and nuclear conditions of matter.

J.G. Pratt & H. Forwald: Confirmation of the PK placement effect.

A study of psychokinesis in its relation to physical conditions.

H. Forwald: Experiments with alternating PK placement and control tests.

C.D. Broad: Dr. S.G. Soals forskning i telepati och framtidsförnimmelse.