Analysis of information sources in references of the Wikipedia article "Volume (bibliography)" in English language version.
rft.part […] Part can be a special subdivision of a volume or it can be the highest level division of the journal. Parts are often designated with letters or names, i.e. "B", "Supplement".
rft.part […] Part can be a special subdivision of a volume or it can be the highest level division of the journal. Parts are often designated with letters or names, i.e. "B", "Supplement".