Fichera, E., S. Mancuso, and A. Pugliano. 2015. “Campaign for Determining the Longitude of the Fundamental Point of the Astronomic Observatory in Naples — II. - Preliminary Study of an Impersonal Micrometer”. The International Hydrographic Review 45 (1). https://journals.lib.unb.ca/index.php/ihr/article/view/23989.