- Persée: This website describes the locality of Santa Paolina in Filottrano, known for its Gallic Senones archaeological finds. A Gallic necropolis with an important burial ground is mentioned.
- Altra Linea Edizioni: This source discusses the historical residences of Filottrano, emphasizing the importance of noble families such as the Perozzi, the Palmucci, and the Spallicci. The historic center was expanded between the Middle Ages and the Renaissance.
- Istituto Storia Marche: This institute mentions Filottrano in the context of the Second World War, even though it was not directly involved in the Val Musone massacre.
- La Rucola: This article discusses the origin of Filottrano and its historical centrality in the Piceno territory, with references to its strategic position.
- Il Postalista: This website discusses the postal history of Filottrano, mentioning its ancient name “Monte Filottrano” and its structure as a walled oppidum.