"Mathematics Philosophy." . . "Magic squares." . . "Circle-squaring." . . . . . "Mathematical essays and recreations"@en . "Mathematical essays and recreations" . . . . . . "Mathematical essays and recreations From the German by Thomas J. McCormack"@en . . . . . . . . . . . . . . . "Mathematical Essays and Recreations"@en . "Mathematical Essays and Recreations" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "Hyperspace." . .