H80-16/053 Wilking Collection, WY Butane Company Building, Casper, WY, https://drive.google.com/file/d/0BwGs7_2V6bvEd2VOaTZHUTZ5eGc/view?usp=drive_link&resourcekey=0-LBccTgZJfatTDg81wdirqw. Wyoming State Archives, Wyoming Cultural Resources Division, Wyoming Department of State Parks & Cultural Resources.

H80-16/053 Wilking Collection, WY Butane Company Building, Casper, WY, https://drive.google.com/file/d/0BwGs7_2V6bvEd2VOaTZHUTZ5eGc/view?usp=drive_link&resourcekey=0-LBccTgZJfatTDg81wdirqw. Wyoming State Archives, Wyoming Cultural Resources Division, Wyoming Department of State Parks & Cultural Resources. https://wyocomet.wyo.gov/repositories/2/digital_objects/4352 Accessed December 05, 2025.