Calcaterra, Domenico; Cappelletti, Piergiulio; Langella, Alessio; Morra, Vincenzo; Colella, Abner; de Gennaro, Roberto (1. desember 2000). «The building stones of the ancient centre of Naples (Italy): Piperno from Campi Flegrei. A contribution to the knowledge of a long-time-used stone». Journal of Cultural Heritage. 4. 1: 415–427. ISSN1296-2074. doi:10.1016/S1296-2074(00)01097-9. Besøkt 31. august 2019. «Piperno, a Late Quaternary magmatic rock cropping out on the eastern side of the Campi Flegrei (Italy), is probably the most important building stone of Naples, used over a time-span from at least the Roman age until the beginning of the 20th century. Despite its wide diffusion in the monumental architecture of Naples, very little is known about this rock, as regards its technical features, as well as the geological aspects. … Main mineralogical, petrographical and engineering–geological properties are presented here for the first time, with specific reference to two sampling areas, located at Pianura and Soccavo, in the western sector of the Neapolitan urban area. As far as many of its physico–mechanical features are concerned, Piperno extends over a wide range of values, which allow different varieties of the rock to be identified.»
Lane, Anthony (16. februar 2009). «Gritty Cities». New Yorker(engelsk). ISSN0028-792X. Besøkt 31. august 2019. «(some Italian audiences required subtitles for “Gomorrah,” so parochial is the Neapolitan dialect)»
Calcaterra, Domenico; Cappelletti, Piergiulio; Langella, Alessio; Morra, Vincenzo; Colella, Abner; de Gennaro, Roberto (1. desember 2000). «The building stones of the ancient centre of Naples (Italy): Piperno from Campi Flegrei. A contribution to the knowledge of a long-time-used stone». Journal of Cultural Heritage. 4. 1: 415–427. ISSN1296-2074. doi:10.1016/S1296-2074(00)01097-9. Besøkt 31. august 2019. «Piperno, a Late Quaternary magmatic rock cropping out on the eastern side of the Campi Flegrei (Italy), is probably the most important building stone of Naples, used over a time-span from at least the Roman age until the beginning of the 20th century. Despite its wide diffusion in the monumental architecture of Naples, very little is known about this rock, as regards its technical features, as well as the geological aspects. … Main mineralogical, petrographical and engineering–geological properties are presented here for the first time, with specific reference to two sampling areas, located at Pianura and Soccavo, in the western sector of the Neapolitan urban area. As far as many of its physico–mechanical features are concerned, Piperno extends over a wide range of values, which allow different varieties of the rock to be identified.»
«Historic Centre of Naples». UNESCO World Heritage Centre(engelsk). UNESCO. Besøkt 30. august 2019. «From the Neapolis founded by Greek settlers in 470 B.C. to the city of today, Naples has retained the imprint of the successive cultures that emerged in Europe and the Mediterranean basin. This makes it a unique site, with a wealth of outstanding monuments such as the Church of Santa Chiara and the Castel Nuovo.»
Lane, Anthony (16. februar 2009). «Gritty Cities». New Yorker(engelsk). ISSN0028-792X. Besøkt 31. august 2019. «(some Italian audiences required subtitles for “Gomorrah,” so parochial is the Neapolitan dialect)»
Calcaterra, Domenico; Cappelletti, Piergiulio; Langella, Alessio; Morra, Vincenzo; Colella, Abner; de Gennaro, Roberto (1. desember 2000). «The building stones of the ancient centre of Naples (Italy): Piperno from Campi Flegrei. A contribution to the knowledge of a long-time-used stone». Journal of Cultural Heritage. 4. 1: 415–427. ISSN1296-2074. doi:10.1016/S1296-2074(00)01097-9. Besøkt 31. august 2019. «Piperno, a Late Quaternary magmatic rock cropping out on the eastern side of the Campi Flegrei (Italy), is probably the most important building stone of Naples, used over a time-span from at least the Roman age until the beginning of the 20th century. Despite its wide diffusion in the monumental architecture of Naples, very little is known about this rock, as regards its technical features, as well as the geological aspects. … Main mineralogical, petrographical and engineering–geological properties are presented here for the first time, with specific reference to two sampling areas, located at Pianura and Soccavo, in the western sector of the Neapolitan urban area. As far as many of its physico–mechanical features are concerned, Piperno extends over a wide range of values, which allow different varieties of the rock to be identified.»