XPS reference (Thermofischer Scientific) - database of investigations by XPS: main regions of investigations, peaks energies, spectra
X-ray properties of the elements (Berkeley Lab) - database of investigations of elements with XPS: peaks energies
NIST X-ray Photoelectron Spectroscopy Database - database of investigations of elements with XPS
ESCALAB Xi X-ray Photoelectron Spectrometer (XPS) Microprobe (Thermofischer Scientific) - description of photoelectron spectrometer ESCALAB Xi, sheet Resources contains XPS data and data about work and specrometer