Incoming Resources
- C. Helm;, Rowman and Littlefield, London, Totowa, N.J, 1978
- C. Helm;, St. Martin's Press, London, New York, 1983
- C. Helm;, Rowman and Littlefield, London, Totowa, N.J, 1977
- C. Helm;, Barnes & Noble, London, Totowa, N.J, 1983
- C. Helm;, St. Martin's Press, London, New York, 1982