Mathematical Excursions - Helen a.merrill
Mathematical Entertainments - A Collection of Illuminating Puzzles, New and Old
My Best Puzzles in Mathematics - Hubert Phillips
Inceasing Eff AC MOTORS
Electrical Products and Solutions - November 2010
Projected Costs of Generating Electricity 2010
Odd Angles 33 Mathematical Entertainments - Charles F
Number Play - Gyles Brandreth