title: Comment on "Coherent Extreme Ultraviolet Light Amplification by Strong-Field-Enhanced Forward Scattering".
authors.affiliation: Max-Born-Institut, Max-Born-Straße 2A, 12489 Berlin, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Bredtmann
authors.affiliation: Max-Born-Institut, Max-Born-Straße 2A, 12489 Berlin, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Patchkovskii
authors.affiliation: Max-Born-Institut, Max-Born-Straße 2A, 12489 Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Ivanov