[2] RFC 3073 - Portable Font Resource (PFR) - application/font-tdpfr MIME Sub-type Registration
( 版)
<https://tools.ietf.org/html/rfc3073>
[4] TrueDoc - Bitstream
( 版)
<http://web.archive.org/web/20040603123430/http://www.bitstream.com/categories/developer/truedoc/pfrspec.html>