diff --git a/scripts/ref b/scripts/ref
new file mode 100755
index 0000000..bdaa471
--- /dev/null
+++ b/scripts/ref
@@ -0,0 +1,41 @@
+#!/bin/sh
+
+# Generate a CSL bibliography entry from a DOI or ISBN
+
+if test "${1#*10.}" != "$1"; then
+  # DOI
+  curl -sLH 'Accept: application/x-bibtex' "https://doi.org/$1" \
+  | pandoc -f bibtex -t markdown -s
+else
+  # ISBN
+  oclc=$(curl -sI "https://www.worldcat.org/isbn/$1" \
+       | sed -nE '/^Location:/ {s@.*oclc/([0-9]+).*@\1@p; q}')
+
+  curl -s "https://openlibrary.org/api/volumes/brief/isbn/$1.json" \
+  | jq --arg oclc "$oclc" '
+    def splitname:
+      split(" ") | {family: .[-1], given: .[0:-1] | map (.[0:1] + ".")| join(" ")};
+    [.records | .[]] | .[0] as $reply
+    | ($reply.data + $reply.details) as $data
+    | [{author: $data.authors | map(.name | splitname),
+        isbn: $data.identifiers.isbn_10[0],
+        edition: $data.details.edition_name | split(" ") | .[0] | sub("[a-z]+"; ""),
+        issued: $data.publish_date,
+        publisher: $data.details.publishers[0],
+        "publisher-place": $data.details.publish_places[0],
+        type: "book",
+        title: $data.title,
+        url: ("https://www.worldcat.org/oclc/" + $oclc)}]' \
+  | pandoc -f csljson -t markdown -s
+fi | sed '
+# delete start of header
+1,3d
+# insert the reference id
+/^- / {i - id: CHANGE_ME
+s/- /  /
+}
+# unquote the url
+/url:/ s/"//g
+# delete end of header
+/^---/d
+$d'