DC Components Co Ltd
Manufacturer of diode rectifiers, bridge rectifiers, axial lead rectifiers, surface mount rectifiers.
http://www.dccomponents.com/

GD Rectifiers Ltd
Custom power semi conductors, including single and three phase selenium rectifier bridges, power modules and heatsink assemblies.
http://www.gdrectifiers.co.uk

Wei Yeu Enterprise Co., Ltd.
OEM supplier for rectifiers and bridges, automotive rectifiers and LED, promoter for lithium-ion, battery packs for cellular phone.
http://www.weiyeu.com.tw/

Harmer & Simmons
DC Power Supplies and switch mode rectifiers for telecoms. Modular power systems integrate rectifiers, alarm, distribution, low volts disconnect, power management systems and battery backup. UK based.
http://www.harmerandsimmons.com/

It's Elemental: Selenium
The Element Selenium - Basic Physical and Historical Information
http://education.jlab.org/itselemental/ele034.html

LANL: Selenium
Production, properties, isotopes, and handling.
http://periodic.lanl.gov/elements/34.html

ChemicalElements.com: Selenium
Basic information, atomic structure, and isotopes.
http://www.chemicalelements.com/elements/se.html

Selenium
Manufacturer of drivers and accessories for home and professional industries. Portugal.
http://www.seleniumloudspeakers.com

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

ChemGlobe: Selenium
The chemical element [Se] - Selenium - Datasheet
http://partisans.spurious.biz/~pkremer/projects/chemglobe/ptoe/_/34.html