https://www.academia.edu/909583/De_la_ballestilla_al_sextante_an%C3%A1lisis_de_dos_centros_de_formaci%C3%B3n_n%C3%A1utica_en_la_Espa%C3%B1a_del_siglo_XVIII_From_the_Cross_staff_to_the_Sextant_the_Analysis_of_Two_Nautical_Educational_Institutions_in_the_Eighteenth_Century?email_work_card=view-paper