diff --git a/test/pdfs/cable.pdf.link b/test/pdfs/cable.pdf.link
index 671f0616..ea10a31e 100644
--- a/test/pdfs/cable.pdf.link
+++ b/test/pdfs/cable.pdf.link
@@ -1 +1 @@
-https://wrap-on.com/docs/PIPEHEATCABLE.PDF
+http://web.archive.org/web/20160112201933/http://www.morelectricheating.com/Customer/moelhe/product_pdf_info/Wrap_On_PreTerminated_Pipe_Heating_Cable_Installation_Instructions.pdf
diff --git a/test/pdfs/fips197.pdf.link b/test/pdfs/fips197.pdf.link
index 815eb1d4..079cc52c 100644
--- a/test/pdfs/fips197.pdf.link
+++ b/test/pdfs/fips197.pdf.link
@@ -1 +1 @@
-http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf
+http://web.archive.org/web/20150225222334/http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf
diff --git a/test/pdfs/fit11-talk.pdf.link b/test/pdfs/fit11-talk.pdf.link
index af7107ee..0a7de713 100644
--- a/test/pdfs/fit11-talk.pdf.link
+++ b/test/pdfs/fit11-talk.pdf.link
@@ -1 +1 @@
-http://www.ccs.neu.edu/home/samth/fit11-talk.pdf
+http://web.archive.org/web/20150126103740/http://www.ccs.neu.edu/home/samth/fit11-talk.pdf
diff --git a/test/pdfs/geothermal.pdf.link b/test/pdfs/geothermal.pdf.link
index 6a255647..85cafd28 100644
--- a/test/pdfs/geothermal.pdf.link
+++ b/test/pdfs/geothermal.pdf.link
@@ -1 +1 @@
-http://geothermal.inel.gov/publications/future_of_geothermal_energy.pdf
+http://web.archive.org/web/20150212141833/http://geothermal.inel.gov/publications/future_of_geothermal_energy.pdf
diff --git a/test/pdfs/hmm.pdf.link b/test/pdfs/hmm.pdf.link
index 521d005e..14b3c1ba 100644
--- a/test/pdfs/hmm.pdf.link
+++ b/test/pdfs/hmm.pdf.link
@@ -1 +1 @@
-http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.145.4773&rep=rep1&type=pdf
+http://web.archive.org/web/20160106162920/http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.145.4773&rep=rep1&type=pdf