1. T. B. PIERCE in P. F. KANE, G. B. LARABEE (Eds), Characterisation of Solid Surfaces, Plenum, New York (in the press).
2. T. B. PIERCE, P. F. PECK, D. R. A. CUFF, Nucl. Instr. Methods, 67 (1969) 1.
3. J. A. COOKSON, A. T. G. FERGUSON, F. D. PILLING in G. DECONNINCK, G. DEMORTIER, F. BODART (Eds), Proc. Intern. Meeting on Chemical Analysis by Charged Particle Bombardment, Namur 6–8 Sept. 1971. Akadémiai Kiadó, Budapest, 1972, see also J. Radioanal. Chem., 12 (1972) 39.
4. T. B. PIERCE, P. F. PECK, D. R. A. CUFF, Analyst 97 (1972) 171.