Published in Proceedings of the California Academy of Sciences, in 1993, in volume 48, pages 119-130

Published in Proceedings of the California Academy of Sciences, in 1993, in volume 48, pages 131-140

Published in Proceedings of the California Academy of Sciences, in 1993, in volume 48, pages 141-152

Published in Proceedings of the California Academy of Sciences, in 1993, in volume 48, issue 4, pages 109-118

Published in Proceedings of the California Academy of Sciences, in 1993, in volume 48, issue 8, pages 153-169