1. An investigation of lead sulphide darkening of nineteenth century painting materials;Carlyle,1990
2. Vogel's Qualitative Inorganic Analysis;Svehla,1996
3. The reversion of blackened lead white on paper;Daniels,1992
4. G.D. Smith, A. Derbyshire, R.J.H. Clark, In situ spectroscopic detection of PbS on a blackened manuscript illumination by Raman microscopy, Stud. Conserv., in press
5. Raman spectroscopic library of natural and synthetic pigments (pre ∼ 1850 A.D.);Bell;Spectrochim. Acta A,1997