Recent progress on the BIPM watt balanceHao Fang, Adrien Kiss, Lennart Robertsson, Estefania de Mirandés, Stéphane Solve, Thomas Lavergne, Alain Picard and Michael StockEPJ Web of Conferences, 77 (2014) 00023DOI: https://doi.org/10.1051/epjconf/20147700023