The inspiration for this came from one of Emperor Tigerstar's map animations.
A ton of Wikipedia pages.
The Crimean War: A History by Orlando Figes (Even though I think he over-exaggerates religion's role during the war.)
1848:Year of Revolution by Mike Rapport for Austrian capabilities.
The HarperCollins Atlas of World History, Second Revised Edition, Chief Editor, Geoffrey Barraclough, for a ton of statistics, especially logistical and economical.
All maps are drawn in GIMP, based off stuff from The Blank Atlas. Specific maps are listed below. I've used a large number of YouTube mapper's videos, and they are underlined, indented from their channel of origin.