Spell, William D. "Portable Charcoal Igniters or Ignition Systems and Apparatus Relating Thereto." U.S. Patent number 4422435. Washington DC: United States Patent and Trademark Office, 1983.

Spell, William D. "Portable Charcoal Igniters or Ignition Systems and Apparatus Relating Thereto." U.S. Patent number 4422435. Washington DC: United States Patent and Trademark Office, 1983.