Annick Mathey, Wim Van Roy, Luc Van Vaeck, Gert Eckhardt, Wolfgang Steglich (1994). In situ analysis of a new perylene quinone in lichens by Fourier-transform laser microprobe mass spectrometry with external source. Rapid Communications in Mass Spectrometry. 8 (1): 46—52. Bibcode:1994RCMS....8...46M. doi:10.1002/rcm.1290080109.
Annick Mathey, Wim Van Roy, Luc Van Vaeck, Gert Eckhardt, Wolfgang Steglich (1994). In situ analysis of a new perylene quinone in lichens by Fourier-transform laser microprobe mass spectrometry with external source. Rapid Communications in Mass Spectrometry. 8 (1): 46—52. Bibcode:1994RCMS....8...46M. doi:10.1002/rcm.1290080109.