"Ion losses at the entrance of a field-free conductance tube into vacuum" by Ross Willoughby, Edward Sheehan, David Fries (ASMS 2009, abstract).

"Studies of ion transmission from atmospheric pressure into vacuum through conductance openings" by Ross C. Willoughby, Edward W. Sheehan, David P. Fries (ASMS 2008, poster).

Fries, D., Ivanov, S., Broadbent, H., Willoughby, R., Sheehan, E., "Micro ion-optical systems technology [MIST] for mass spectrometry using PCBMEMS," 2007 IEEE Intetrnational Symposium on Inductrial Electonics, pages 3278-3281, Vigo, Spain (June 4-7, 2007).

"Ion enrichment aperture arrays" by Edward W Sheeand, Ross C Willoughby, US Patent 7,060,976 (June 13, 2006).

"Aperture arrays for atmospheric pressure sources" by Edward W Sheehan, Ross C Willoughby, David Fries (ASMS 2006, poster).

"Micro ion-optical systems technology [MIST] for atmospheric pressure sources" by David Fries, Ross Willoughby, Edward Sheehan, George Steimle, Stan Invanov (ASMS 2006, poster).

"Laminate tube for the transport of charged particles contained in a gaseous medium" by Ross C Willoughby, Edward W Sheehan, US Patent 6,943,347, (September 13, 2005).

"Ion enrichment aperture arrays" by Edward W Sheeand, Ross C Willoughby, US Patent 6,914,243 (July 5, 2005).

"Transmission of ions through laminated conductance pathways from atmospheric pressure" by Ross Willoughby, Edward Sheehan, David Fries (ASMS 2005, poster).

"Ion enrichment aperture arrays" by Edward W Sheeand, Ross C Willoughby (WO Patent 2004/110583 A2, December 23, 2004).

"Transmission of ions through conductance pathways from atmospheric pressure" by Ross C. Willoughby, Edward W. Sheehan, David Fries (ASMS 2004, abstract).

"Atmospheric pressure focusing" by Edward W Sheehan, Ross C Willoughby, David Fries (ASMS 2004, abstract)

"Atmospheric pressure focusing" by Edward W Sheehan, Ross C Willoughby, David Fries (ASMS 2004, poster PowerPoint)