On complex matrices that are unitarily similar to real matrices

There are well-known conditions ensuring that a complex n x n matrix A can be converted by a similarity transformation into a real matrix. Is it possible to realize this conversion via unitary similarity rather than a general one? The following answer to this question is given in this paper: A matrix A a M (n) (a",) can be made real by a unitary similarity transformation if and only if A and AEuro are unitarily similar and the matrix P transforming A into AEuro can be chosen unitary and symmetric at the same time. Effective ways for verifying this criterion are discussed.