Nickel

ChemGlobe: Nickel - Electronic, thermal, and steric data along with an isotope table.
partisans.spurious.biz/~pkremer/projects/chemglobe/ptoe/_/28.html

ChemicalElements.com: Nickel - Basic information, atomic structure, and isotopes.
www.chemicalelements.com/elements/ni.html

EnvironmentalChemistry.com: Nickel - Atomic structure, chemical and physical properties, and table of nuclides.
environmentalchemistry.com/yogi/periodic/Ni.html

It's Elemental: Nickel - Basic physical and historical information.
education.jlab.org/itselemental/ele028.html

LANL: Nickel - Sources, properties, and uses.
periodic.lanl.gov/elements/28.html

Lenntech: Nickel - Physical data, chemical properties, health and environmental effects.
www.lenntech.com/Periodic-chart-elements/Ni-en.htm

USGS Minerals Information: Nickel - Statistics and information on the worldwide supply, demand, and flow of the element (PDF format).
minerals.usgs.gov/minerals/pubs/commodity/nickel/

Visual Elements: Nickel - Image, general and physical information, source, uses, key isotopes, and ionisation energies.
www.chemsoc.org/viselements/pages/nickel.html

Wikipedia: Nickel - Properties of the element, including its history, applications, and characteristics.
en.wikipedia.org/wiki/Nickel

Radiochemistry of Nickel - Full text of the monograph by L. J. Kirby (Hanford Atomic Products Operation, Richland, Washington). [PDF] <small>(November, 1961)</small>
lib-www.lanl.gov/cgi-bin/getfile=3frc000008.pdf