The conversation between human and AI assistant.
[|Human|] Given these paragraphs about Natural hydrogen, can you name some of the countries where sources have been identified?
[|AI|] Several sources have been identified in France. Geologists Alain Prinzhofer and Eric Derville have demonstrated the existence of large reservoirs in a dozen countries, including Mali and the United States. However, their potential remains difficult to assess.
[|Human|] 
Given these paragraphs about Natural hydrogen, can you name some of the countries where sources have been identified?