Non-Gaussianity and secondary gravitational waves from primordial black holes production in -attractor inflationKazem Rezazadeh, Zeinab Teimoori, Saeid Karimi and Kayoomars KaramiEur. Phys. J. C, 82 8 (2022) 758DOI: https://doi.org/10.1140/epjc/s10052-022-10735-w