Index: doc/bibliography/cfa.bib
===================================================================
--- doc/bibliography/cfa.bib	(revision 8bcaf2153e69191156a09e255e9103b37ffc4249)
+++ doc/bibliography/cfa.bib	(revision 678765c4d892f71dc08ae4d5f9684af5f3e00fba)
@@ -3035,4 +3035,14 @@
     year	= 1992,
     pages	= {T1-53},
+}
+
+@manual{GMP,
+    keywords	= {GMP arbitrary-precision library},
+    contributer	= {pabuhr@plg},
+    title	= {{GNU} Multiple Precision Arithmetic Library},
+    author	= {GMP},
+    organization= {GNU},
+    year	= 2016,
+    note	= {\href{https://gmplib.org}{https://\-gmplib.org}},
 }