1. Shibata, S., Miyaji, T., Ohba, Y., Yamamoto, K., and Hamilton, H. B., unpublished data.
2. The Molar Light Absorption of Pyridine Ferroprotoporphrin (Pyridine Haemochromogen).
3. Imai, K., Morimoto, H., Kotani, M., Watari, H., Hirata, W., and Kuroda, M., to be submitted.
4. Shibata, S., and Miyaji, T., personal communication.