1817-5996 1817-5996 S1817-59962021000100001 Peru Perú 00 04 2021 00 04 2021 23 1 1 2020 22 2 2 1-16 2 2018 1 367-74 3 2020 4 1961 5 2017 14 5 5 545-55 6 2017 9 12 12 1278-82 7 2018 18 1 1 178 8 2020 20 1-12 9 2021