Given the lack of direct information, the best approach is to ask the user for clarification. They might be referring to a self-published work, an academic paper, or a niche publication. It's possible that "vol13 20_upd" is part of their internal version control system, like a draft number. Alternatively, the "20" could relate to a chapter or specific section within the volume that's been updated.
Since my knowledge is current up to 2023, if the "20" in the query refers to 2020 or 2023, I should consider that timeframe. There's also the chance that "20_upd" is a file format or a code part of a larger system, not directly related to the volume itself. roy stuart glimpse vol13 20 upd
Summarizing the possibilities: a book series, technical documentation, software product, or another publication type. The key points are the volume number and the update version, with "upd" likely indicating an update. The user might need information on where to access this updated version, if available, or confirmation about its existence. Given the lack of direct information, the best