I'm having difficulty finding some secondary data on the extraction of radium or polonium. Nothing specific, really just any practical data available on the topic - I'm getting desperate! Historical data would be preferable, however modern data would still be great. By 'data' I just been any experimental data on how the process of radium/polonium extraction takes place (masses of each element in the ore, radioactivity levels, anthing!). I know this seems like a vague thing to be looking for - I just need to analyze any data related to the topic.