Document 692
Ferns, P. N., R.J. Cowie, J. Simons and R. Woodburn. 1994. Monitoring Bird Activity on British Airfields. Proceedings of the International Bird Strike Committee, Vienna, Austria IBSC22/WP56:333-342.
Ferns, P. N., R.J. Cowie, J. Simons and R. Woodburn. 1994. Monitoring Bird Activity on British Airfields. Proceedings of the International Bird Strike Committee, Vienna, Austria IBSC22/WP56:333-342.
