title: Comment on "Viable singularity-free f(R) gravity without a cosmological constant".
authors.affiliation: Departamento de Física Teórica, Universidad Complutense de Madrid, 28040 Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: de la Cruz-Dombriz
authors.forename: A
authors.initials: A
authors.lastname: Dobado
authors.forename: A L
authors.initials: AL
authors.lastname: Maroto