This Cambridge archaeobotany group have also provided a recent review of ~5000 BC and earlier millets reported from across Eurasia in a recent Vegetation History and Archaeobotany [open access]. A useful compilation in particular as it has made reference to hard to obtain sources published in Chinese and Russian. I remain unconvinced of Jones' (2004) hypothesis that Panicum miliaceum was an early Neolithic crop dispersal from East Asia to Europe. The Early European data is quite thin on the ground and may well represent weedy/wild material, or a separate origin as millet crept into East European cultivation. Striking is the evidence for a late (i.e. Bronze Age dispersal out of China) of Setaria italica and other Chinese domesticates.
Here is the link to their "East-West Millet Project" website.