1. Johnson BD. Spectral imaging finds a place on the farm. Photonics Spectra Magazine, January 2002, Laurin Publishing, 2002.
2. Directions in Environmental Spectroscopy, Spectroscopy Showcase Magazine, March 1999.
3. Putz H-J, Göttsching L. Altpapier – Ist sein Einsatz noch zu steigern?. Das Papier 2001 – T189.
4. Spotlight on paper collection and recycling: challenges and opportunities of the future. Brussels 28th October 2002.
5. Hyvarinen T, Herrala E, Dall’Ava A. Direct sight imaging spectrograph: a unique add-on component brings spectral imaging to industrial applications. SPIE 1998, symposium on electronic imaging in conference 3302, 1998.