Surface layer impurities on silicon spheres used in determination of the Avogadro constant. - Michael J. Kenny; Roger P. Netterfield; Leszek S. Wielunski; David Beaglehole (IEEE Trans. Instrum. Meas., 1999)

Precision determination of the density of a single crystal silicon sphere and evaluation of the Avogadro constant. - Michael J. Kenny; Achim J. Leistner; Christopher J. Walsh; Kitty Fen; Walter Giardini; Leszek S. Wielunski; Roger P. Netterfield; Bradley R. Ward (IEEE Trans. Instrum. Meas., 2001)