Norton, G.H. Salagean, Ana On the stucture of linear and cyclic codes over finite chain rings We generalise structure theorems of Calderbank and Sloane for linear and cyclic codes over Zpa to a finite chain ring. Our results are more detailed and do not use non-trivial results from Commutative Algebra. Finite chain ring;Galois ring;Linear code;Cyclic code;Information and Computing Sciences not elsewhere classified 2006-08-21
    https://repository.lboro.ac.uk/articles/journal_contribution/On_the_stucture_of_linear_and_cyclic_codes_over_finite_chain_rings/9401618