diff --git a/bibliography.adoc b/bibliography.adoc
index 926e1b0d..5caf23b4 100644
--- a/bibliography.adoc
+++ b/bibliography.adoc
@@ -7,17 +7,15 @@
 Sponsored by the "Cooperative Ocean/Atmosphere Research Data Service," a NOAA/university cooperative for the sharing and distribution of global atmospheric and oceanographic research data sets. May 1995.
 - [[[FGDC]]]  link:$$http://www.fgdc.gov/standards/projects/FGDC-standards-projects/metadata/base-metadata/v2_0698.pdf$$[Content Standard for Digital Geospatial Metadata].
 Federal Geographic Data Committee, FGDC-STD-001-1998.
-- [[[IEEE_754]]]  link:$$https://ieeexplore.ieee.org/servlet/opac?punumber=8766227$$[IEEE Standard for Floating-Point Arithmetic], in __IEEE Std 754-2019 (Revision of IEEE 754-2008)__, vol., no., pp.1-84, 22 July 2019, doi: 10.1109/IEEESTD.2019.8766229.
-- [[[NetCDF]]]  link:$$http://www.unidata.ucar.edu/netcdf/index.html$$[NetCDF Software Package].  UNIDATA Program Center of the University Corporation for Atmospheric Research.
+- [[[IEEE_754]]]  link:$$https://doi.org/10.1109/IEEESTD.2019.8766229$$[IEEE Standard for Floating-Point Arithmetic], in _IEEE Std 754-2019 (Revision of IEEE 754-2008)_, 22 July 2019.
+- [[[NetCDF]]]  link:$$https://doi.org/10.5065/D6H70CW6$$[NetCDF Software Package].  UNIDATA Program Center of the University Corporation for Atmospheric Research.
 - [[[NUG]]]  link:$$https://docs.unidata.ucar.edu/nug/current/index.html$$[The NetCDF User's Guide].
 - [[[OGC_WKT-CRS]]]  link:$$http://www.opengeospatial.org/standards/wkt-crs$$[OGC Well-known text representation of coordinate reference systems].
 OGC document 12-063. 1st May 2015.
-- [[[OGP-EPSG]]]  link:$$http://www.epsg.org$$[OGP Surveying & Positioning Committee] and link:$$http://www.epsg-registry.org$$[EPSG Geodetic Parameter Registry].
-- [[[OGP-EPSG_GN7_2]]]  link:$$http://www.epsg.org$$[OGP Surveying and Positioning Guidance Note 7, part 2: Coordinate Conversions and Transformations including Formulas].
-- [[[SCH02]]] C Schaer, D Leuenberger, and O Fuhrer. 2002. {ldquo} A new terrain-following vertical coordinate formulation for atmospheric prediction models {rdquo}.
-_Monthly Weather Review__.  130. 2459-2480.
+- [[[OGP-EPSG_GN7_2]]]  link:$$https://epsg.org/guidance-notes.html$$[OGP Surveying and Positioning Guidance Note 7, part 2: Coordinate Conversions and Transformations including Formulas].
+- [[[SCH02]]] link:$$https://doi.org/10.1175/1520-0493(2002)130<2459:ANTFVC>2.0.CO;2$$[A new terrain-following vertical coordinate formulation for atmospheric prediction models]. C Schaer, D Leuenberger, and O Fuhrer. 2002. _Monthly Weather Review_.  130. 2459-2480.
 - [[[Snyder]]]  link:$$https://doi.org/10.3133/pp1395$$[Map Projections: A Working Manual]. USGS Professional Paper 1395.
-- [[[UDUNITS]]]  link:$$http://www.unidata.ucar.edu/software/udunits/$$[UDUNITS Software Package].  UNIDATA Program Center of the University Corporation for Atmospheric Research.
+- [[[UDUNITS]]]  link:$$https://doi.org/10.5065/D6KD1WN0$$[UDUNITS Software Package].  UNIDATA Program Center of the University Corporation for Atmospheric Research.
 - [[[W3C]]]  link:$$http://www.w3.org/$$[World Wide Web Consortium (W3C)].
 - [[[XML]]]  link:$$http://www.w3.org/TR/1998/REC-xml-19980210$$[Extensible Markup Language (XML) 1.0]. T. Bray, J. Paoli, and C.M. Sperberg-McQueen.  10 February 1998.
-- [[[CFDM]]]  link:$$http://doi.org/10.5194/gmd-10-4619-2017$$[A data model of the Climate and Forecast metadata conventions (CF-1.6) with a software implementation (cf-python v2.1)]. Hassell, D., Gregory, J., Blower, J., Lawrence, B. N., and Taylor, K. E.: Geosci. Model Dev., 10, 4619-4646, https://doi.org/10.5194/gmd-10-4619-2017, 2017.
+- [[[CFDM]]]  link:$$http://doi.org/10.5194/gmd-10-4619-2017$$[A data model of the Climate and Forecast metadata conventions (CF-1.6) with a software implementation (cf-python v2.1)]. Hassell, D., Gregory, J., Blower, J., Lawrence, B. N., and Taylor, K. E.: _Geosci. Model Dev._, 10, 4619-4646, 2017.
diff --git a/history.adoc b/history.adoc
index dfbf82cd..e201acc9 100644
--- a/history.adoc
+++ b/history.adoc
@@ -4,6 +4,7 @@
 
 [[revhistory, Revision History]]
 == Revision History
+* {issues}266[Issue #266]: Updates to some links in the bibliography
 * {issues}405[Issue #405]: Update ch. 4.4 text on reference time vs. UDUNIT
 * {issues}406[Issue #406]: Remove duplicate section 8.2 in the conformance document
 * {issues}391[Issue #391]: Correct link to Snyder and typo in the bibliography