- Электронная книгаLetters on Astronomy in which the Elements of the Science are Familiarly Explained in Connection with Biographical Sketches of the Most Eminent AstronomersDenison Olmsted
- Электронная книгаLetters on Astronomy in which the Elements of the Science are Familiarly Explained in Connection with Biographical Sketches of the Most Eminent AstronomersDenison Olmsted