Lehrbuch der Bahnbestimmung der Kometen und Planeten This book, "Lehrbuch der Bahnbestimmung der Kometen und Planeten. 2", by Theodor Oppolzer, is a replication of a book originally published before 1880. It has been restored by human beings, page by page, so that you may enjoy it in a form as close to the original as possible. This book was created using print-on-demand technology. Thank you for supporting classic literature.