2024 26 CFR 50.6 – Ascertainment of quantity mined

2023 26 CFR 50.6 – Ascertainment of quantity mined

2022 26 CFR 50.6 – Ascertainment of quantity mined

2021 26 CFR 50.6 – Ascertainment of quantity mined

2020 26 CFR 50.6 – Ascertainment of quantity mined

2019 26 CFR 50.6 – Ascertainment of quantity mined

2016 26 CFR 50.6 – Ascertainment of quantity mined

2015 26 CFR 50.6 – Ascertainment of quantity mined

2014 26 CFR 50.6 – Ascertainment of quantity mined