diff --git a/phpseclib/Crypt/EC/BaseCurves/KoblitzPrime.php b/phpseclib/Crypt/EC/BaseCurves/KoblitzPrime.php
index 0495913c..dba83be4 100644
--- a/phpseclib/Crypt/EC/BaseCurves/KoblitzPrime.php
+++ b/phpseclib/Crypt/EC/BaseCurves/KoblitzPrime.php
@@ -47,7 +47,8 @@ class KoblitzPrime extends Prime
      *
      * Uses a efficiently computable endomorphism to achieve a slight speedup
      *
-     * Adapted from https://git.io/vxbrP
+     * Adapted from:
+     * https://github.com/indutny/elliptic/blob/725bd91/lib/elliptic/curve/short.js#L219
      *
      * @return int[]
      */
diff --git a/phpseclib/Crypt/EC/BaseCurves/Prime.php b/phpseclib/Crypt/EC/BaseCurves/Prime.php
index 6b9ea791..d6fb2bb5 100644
--- a/phpseclib/Crypt/EC/BaseCurves/Prime.php
+++ b/phpseclib/Crypt/EC/BaseCurves/Prime.php
@@ -513,7 +513,8 @@ class Prime extends Base
     /**
      * Multiply and Add Points
      *
-     * Adapted from https://git.io/vxPUH
+     * Adapted from:
+     * https://github.com/indutny/elliptic/blob/725bd91/lib/elliptic/curve/base.js#L125
      *
      * @return int[]
      */
@@ -639,7 +640,8 @@ class Prime extends Base
     /**
      * Precomputes NAF points
      *
-     * Adapted from https://git.io/vxY1f
+     * Adapted from:
+     * https://github.com/indutny/elliptic/blob/725bd91/lib/elliptic/curve/base.js#L351
      *
      * @return int[]
      */
@@ -675,7 +677,8 @@ class Prime extends Base
     /**
      * Precomputes points in Joint Sparse Form
      *
-     * Adapted from https://git.io/vxrpD
+     * Adapted from:
+     * https://github.com/indutny/elliptic/blob/725bd91/lib/elliptic/utils.js#L96
      *
      * @return int[]
      */
diff --git a/phpseclib/Net/SSH2.php b/phpseclib/Net/SSH2.php
index 661cb27a..c9c53cb0 100644
--- a/phpseclib/Net/SSH2.php
+++ b/phpseclib/Net/SSH2.php
@@ -4444,7 +4444,7 @@ class SSH2
             'aes192-ctr',     // RECOMMENDED       AES with 192-bit key
             'aes256-ctr',     // RECOMMENDED       AES with 256-bit key
 
-            // from <https://git.io/fhxOl>:
+            // from <https://github.com/openssh/openssh-portable/blob/001aa55/PROTOCOL.chacha20poly1305>:
             // one of the big benefits of chacha20-poly1305 is speed. the problem is...
             // libsodium doesn't generate the poly1305 keys in the way ssh does and openssl's PHP bindings don't even
             // seem to support poly1305 currently. so even if libsodium or openssl are being used for the chacha20