Thomas Koshy, 80.48 The Euclidean Algorithm via Matrices and a Calculator, The Mathematical Gazette, Vol. 80, No. 489 (Nov., 1996), pp. 570-574 ...

Niels Möller, On Schönhage's Algorithm and Subquadratic Integer GCD Computation, Mathematics of Computation, Vol. 77, No. 261 (Jan., 2008), pp. 589-607 ...

The Euclidean algorithm offers a recipe for finding the greatest common divisor of two whole numbers. Suppose the given numbers are 12 and 18.