Ornstein, Robert E.,

The Mind Field,

Grossman Publishers, New York, 1976.

Ostrander, Sheila and Lynn Schroeder,

Curtain,

Bantam Books, New York, 1970.

Ostrander, Sheila and Lynn Schroeder,

Handbook of Psi Discoveries,

Berkley

Ostwald, Wilhelm,

Unknown page