On extremal self-dual quaternary codes of lengths 18 to 28. II

For pt.I see ibid., vol.36, no.3, p.651-60 (1990). A general decomposition theorem is applied to find all extremal self-dual quaternary codes of lengths 18 to 28 that have a nontrivial monomial automorphism of order a power of 3. Techniques to distinguish these codes are also presented. The author presents situations in which the equivalence of the codes under consideration can be decided.<
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