Probably the first appearance of the 3-fractions puzzle in the constraints literature is [schulte2004finite].
The following paper shows how a basic model of the 3-fractions puzzle can be improved automatically [frisch2001extensions].
Using hand-reformulation, the following paper discusses how different using symmetry-breaking schemes on the 3-fractions puzzle, followed by the derivation of implied constraints, can lead to models of varying quality [frisch2004symmetry].
The following paper investigates the numerical issues arising when the number of fractions grows and two new CP models that exploit the integer factorization of the fractions’ denominators [malapert2017puzzle].
Finite Domain Constraint Programming in Oz. A Tutorial.
Available at www. mozart-oz. org, 2004
Symmetry breaking as a prelude to implied constraints: A constraint modelling pattern
ECAI, 171, 2004
Extensions to proof planning for generating implied constraints
In Proceedings of Calculemus-01, 2001
Puzzle—Solving the n-Fractions Puzzle as a Constraint Programming Problem