"Field-free electrospray nebulizer" by Edward W Sheehan, Ross C Willoughby, US Patent 7,960,711 (June 14, 2011).

"Remote reagent ion generator" by Timothy P Karpetsky, John C Berends, Edward W Sheehand, Ross C Willoughby, US Patent 7,569,812 (August 4, 2009).

"Coupling atmospheric pressure optics with field-free ionization sources" by Edward Sheehan, Ross Willoughby, David Fries (ASMS 2009, abstract).

"Field-free atmospheric ionization: Atmospheric pressure chemical ionization & electrospray" by Edward W. Sheehan1, Ross C. Willoughby, Robert Classon, Dan Dodgen (ASMS 2008, poster).

"Remote reagent chemcial ionization source" by Edward W Sheehand, Ross C Willoughby, US Patent 7,253,406 (August 7, 2007).

"Remote reagent chemcial ionization source" by Edward W Sheehand, Ross C Willoughby, US Patent 7,095,019 (August 22, 2006).

"Remote reagent chemcial ionization source" by Edward W Sheehand, Ross C Willoughby, US Patent 6,888,132 (May 3 2005).