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diff --git a/paper/lua-filters/multiple-bibliographies/multiple-bibliographies.lua b/paper/lua-filters/multiple-bibliographies/multiple-bibliographies.lua
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+++ b/paper/lua-filters/multiple-bibliographies/multiple-bibliographies.lua
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+--[[
+multiple-bibliographies – create multiple bibliographies
+
+Copyright © 2018-2019 Albert Krewinkel
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+]]
+local List = require 'pandoc.List'
+local utils = require 'pandoc.utils'
+local stringify = utils.stringify
+local run_json_filter = utils.run_json_filter
+
+--- Collection of all cites in the document
+local all_cites = {}
+--- Document meta value
+local doc_meta = pandoc.Meta{}
+
+--- Div used by pandoc-citeproc to insert the bibliography.
+local refs_div = pandoc.Div({}, pandoc.Attr('refs'))
+
+local supports_quiet_flag = (function ()
+  local version = pandoc.pipe('pandoc-citeproc', {'--version'}, '')
+  local major, minor, patch = version:match 'pandoc%-citeproc (%d+)%.(%d+)%.?(%d*)'
+  major, minor, patch = tonumber(major), tonumber(minor), tonumber(patch)
+  return major > 0
+    or minor > 14
+    or (minor == 14 and patch >= 5)
+end)()
+
+--- Resolve citations in the document by combining all bibliographies
+-- before running pandoc-citeproc on the full document.
+local function resolve_doc_citations (doc)
+  -- combine all bibliographies
+  local meta = doc.meta
+  local orig_bib = meta.bibliography
+  meta.bibliography = pandoc.MetaList{orig_bib}
+  for name, value in pairs(meta) do
+    if name:match('^bibliography_') then
+      table.insert(meta.bibliography, value)
+    end
+  end
+  -- add dummy div to catch the created bibliography
+  table.insert(doc.blocks, refs_div)
+  -- resolve all citations
+  doc = run_json_filter(doc, 'pandoc-citeproc')
+  -- remove catch-all bibliography
+  table.remove(doc.blocks)
+  -- restore bibliography to original value
+  doc.meta.bibliography = orig_bib
+  return doc
+end
+
+--- Explicitly create a new meta object with all fields relevant for
+--- pandoc-citeproc.
+local function meta_for_pandoc_citeproc (bibliography)
+  -- We could just indiscriminately copy all meta fields, but let's be
+  -- explicit about what's important.
+  local fields = {
+    'bibliography', 'references', 'csl', 'citation-style',
+    'link-citations', 'citation-abbreviations', 'lang',
+    'suppress-bibliography', 'reference-section-title',
+    'notes-after-punctuation', 'nocite'
+  }
+  local new_meta = pandoc.Meta{}
+  for _, field in ipairs(fields) do
+    new_meta[field] = doc_meta[field]
+  end
+  new_meta.bibliography = bibliography
+  return new_meta
+end
+
+--- Create a bibliography for a given topic. This acts on all divs whose
+-- ID starts with "refs", followed by nothing but underscores and
+-- alphanumeric characters.
+local function create_topic_bibliography (div)
+  local name = div.identifier:match('^refs([_%w]*)$')
+  local bibfile = name and doc_meta['bibliography' .. name]
+  if not bibfile then
+    return nil
+  end
+  local tmp_blocks = {pandoc.Para(all_cites), refs_div}
+  local tmp_meta = meta_for_pandoc_citeproc(bibfile)
+  local tmp_doc = pandoc.Pandoc(tmp_blocks, tmp_meta)
+  local filter_args = {FORMAT, supports_quiet_flag and '-q' or nil}
+  local res = run_json_filter(tmp_doc, 'pandoc-citeproc', filter_args)
+  -- First block of the result contains the dummy paragraph, second is
+  -- the refs Div filled by pandoc-citeproc.
+  div.content = res.blocks[2].content
+  return div
+end
+
+return {
+  {
+    -- Collect all citations and the doc's Meta value for other filters.
+    Cite = function (c) all_cites[#all_cites + 1] = c end,
+    Meta = function (m) doc_meta = m end,
+  },
+  { Pandoc = resolve_doc_citations },
+  { Div = create_topic_bibliography },
+}