A Strange Theft (sources)
- "5-Ton Ball Out Of Bounds -- Thief Sought," article in the Indianapolis Star, newspaper of Indianapolis, Indiana, USA, Wednesday, July 18, 1973. Pg. 17, col. 4. Online at Newspapers.com [pay service]: https://www.newspapers.com/image/105801145/?terms=ton%2Bball%2Bdowling
- "Thieves Have Quite A Ball: 5 Tons Of It," article in the Muncie Evening Press, newspaper of Muncie, indiana, USA, Wednesday, July 18, 1973. Pg. 2, col. 3. Online at Newspapers.com [pay service]: https://www.newspapers.com/image/250449919/?terms=ton%2Bball%2Bdowling
- "Real King-Size Collector's Item," article in the Odessa American, newspaper of Odessa, Texas, USA, Wednesday, July 18, 1973. Pg. 11, col. 4. Online at Newspapers.com [pay service]: https://www.newspapers.com/image/301436665/
- "Fumbled the Ball," article in the Indianapolis Star, newspaper of Indianapolis, Indiana, USA, Thursday, July 19, 1973. Pg. 67, col. 4. Online at Newspapers.com [pay service]: https://www.newspapers.com/image/105803281/?terms=ton%2Bball%2Bdowling
- "Wrecking Ball is Missing," article in the Observer-Reporter, newspaper of Washington, Pennsylvania, USA, Thursday, July 19, 1973. Pg. 14, col. 4. Online: https://news.google.com/newspapers?nid=2519&dat=19730719&id=Z-RdAAAAIBAJ&sjid=BV8NAAAAIBAJ&pg=3573,3107811&hl=en
- "Somebody Stole 5-Ton Metal Ball," article in the Mexia Daily News, newspaper of Mexia, Texas, USA, Monday, July 23, 1973. Pg. 5, col. 3. Online at Newspapers.com [pay service]: https://www.newspapers.com/image/36321335/
- "A Heavy Question," article in Mysteries of the Unexplained, 1982 Reader's Digest Association, USA. Fifth printing, February 1985. ISBN: 0-89577-146-2. Pg. 95. Online [snippet view]: https://books.google.com/books?id=MjqcKUX9x74C&q=%22a+heavy+question%22+dowling+construction+company&dq=%22a+heavy+question%22+dowling+construction+company&hl=en&sa=X&ved=0ahUKEwjv192lv_zaAhVC6GMKHU9DA2sQ6AEIJzAA
- "The Reader's Column," by Becky Walter, article in the Indianapolis Star, newspaper of Indianapolis, Indiana, USA, Sunday, October 6, 1985. Pg. 41, col. 1. Online at Newspapers.com [pay service]: https://www.newspapers.com/image/106384078/?terms=%22Dowling%2BConstruction%2BCo%22
- "A Heavy Question," by 'acarter8', post in the Reddit website, posted 2016, viewed 5-10-2018. Online: https://www.reddit.com/r/UnresolvedMysteries/comments/4awaox/a_heavy_question/
- René Magritte (1898-1967): "La reconnaissance infinie", apge in the Christie's website, posted 6-22-2004, viewed 5-20-2018. Online: https://www.christies.com/lotfinder/Lot/rene-magritte-1898-1967-la-reconnaissance-infinie-4317538-details.aspx