Ronald Stoyan is Senior Editor of Abenteuer Astronomie magazine, and the proprietor of the independent German publisher Oculum-Verlag, which specializes in amateur astronomy books. He has authored or co-authored twelve books on practical astronomy, including Atlas of the Messier Objects (Cambridge, 2008), The Cambridge Photographic Star Atlas (Cambridge, 2017), Atlas of Great Comets (Cambridge, 2015) and the interstellarum Deep Sky Atlas (Cambridge, 2014). Uwe Glahn has been an active deep sky observer for more than 25 years. With homemade telescopes of different sizes, he documents his results through classic sketches, which are published regularly in national and international magazines and books. His website, www.deepsky-visuell.de, records all of his results.