diff --git a/docs/source/methods/physics.rst b/docs/source/methods/physics.rst
index c3ee161a75..cc486ab67b 100644
--- a/docs/source/methods/physics.rst
+++ b/docs/source/methods/physics.rst
@@ -1626,7 +1626,7 @@ another.
 
 .. _ENDF-6 Format: http://www-nds.iaea.org/ndspub/documents/endf/endf102/endf102.pdf
 
-.. _Monte Carlo Sampler: https://laws.lanl.gov/vhosts/mcnp.lanl.gov/pdf_files/la-9721_3rdmcsampler.pdf
+.. _Monte Carlo Sampler: https://laws.lanl.gov/vhosts/mcnp.lanl.gov/pdf_files/la-9721.pdf
 
 .. _LA-UR-14-27694: http://permalink.lanl.gov/object/tr?what=info:lanl-repo/lareport/LA-UR-14-27694
 
@@ -1636,4 +1636,4 @@ another.
 
 .. _lectures: https://laws.lanl.gov/vhosts/mcnp.lanl.gov/pdf_files/la-ur-05-4983.pdf
 
-.. _MCNP Manual: https://laws.lanl.gov/vhosts/mcnp.lanl.gov/pdf_files/la-ur-03-1987.pdf 
+.. _MCNP Manual: https://laws.lanl.gov/vhosts/mcnp.lanl.gov/pdf_files/la-ur-03-1987.pdf
diff --git a/docs/source/methods/random_numbers.rst b/docs/source/methods/random_numbers.rst
index 3ea61719c5..e0a974f43b 100644
--- a/docs/source/methods/random_numbers.rst
+++ b/docs/source/methods/random_numbers.rst
@@ -70,5 +70,5 @@ the idea is to determine the new multiplicative and additive constants in
    Different Sizes and Good Lattice Structures," *Math. Comput.*, **68**, 249
    (1999).
 
-.. _Brown: https://laws.lanl.gov/vhosts/mcnp.lanl.gov/pdf_files/anl_rn_arb-strides_1994.pdf
+.. _Brown: https://laws.lanl.gov/vhosts/mcnp.lanl.gov/pdf_files/anl-rn-arb-stride.pdf
 .. _linear congruential generator: http://en.wikipedia.org/wiki/Linear_congruential_generator
diff --git a/docs/source/methods/tallies.rst b/docs/source/methods/tallies.rst
index fd0812245a..65a0989ac7 100644
--- a/docs/source/methods/tallies.rst
+++ b/docs/source/methods/tallies.rst
@@ -507,6 +507,6 @@ improve the estimate of the percentile.
 
 .. _Cauchy distribution: http://en.wikipedia.org/wiki/Cauchy_distribution
 
-.. _unpublished rational approximation: http://home.online.no/~pjacklam/notes/invnorm/
+.. _unpublished rational approximation: https://web.archive.org/web/20150926021742/http://home.online.no/~pjacklam/notes/invnorm/
 
 .. _MC21: http://www.osti.gov/bridge/servlets/purl/903083-HT5p1o/903083.pdf