Herrera, Helios Guillaume Herrera, Helios Hervé Herrera, Helios Hervé Guillaume 26195 2026-03-06 16:25:27 2026-03-06 15:26:16 naf viaf repec author https://fraser.stlouisfed.org/author/helios-herrera https://fraser.stlouisfed.org/api/author/26195