xyzseries - great for one of those winter nights, waiting for the ghost of Christmas past... or future (!)

xyzseries:

XYZ Book Series

XYZ Press publications utilize competition math as the vehicle for introducing students from middle school through college to the elegance of problem-solving through a wide variety of mathematical topics and difficulty levels. Emphasis is placed on developing mathematical insight through interesting problems, many of which employ clever strategies to engage and delight the reader. 

'via Blog this' The Honourable Schoolboy