how to implement cyclic cross over in matlab ?

I found one code on the internet but the input and output is not understandable https://github.com/estsauver/GAOT/blob/master/cyclicXover.m

[John BG]

what Davis reference do you mean, the following one? https://www.amazon.co.uk/Evolutionary-Computation-Practice-Computational-Intelligence/dp/3540757708/ref=sr_1_fkmr0_2?ie=UTF8&qid=1523115799&sr=8-2-fkmr0&keywords=Davis+permutation+strings