Made link of reference

doc/crypto/BN_add.pod

@@ -40,7 +40,7 @@ B<r> may be the same B<BIGNUM> as B<a> or B<b>.
 BN_sub() subtracts B<b> from B<a> and places the result in B<r> (C<r=a-b>).
 
 BN_mul() multiplies B<a> and B<b> and places the result in B<r> (C<r=a*b>).
-For multiplication by powers of 2, use BN_lshift(3).
+For multiplication by powers of 2, use L<BN_lshift(3)|BN_lshift(3)>.
 
 BN_div() divides B<a> by B<d> and places the result in B<dv> and the
 remainder in B<rem> (C<dv=a/d, rem=a%d>). Either of B<dv> and B<rem> may

doc/crypto/RSA_get_ex_new_index.pod

@@ -111,7 +111,7 @@ present in the parent RSA structure when it is called.
 
 =head1 SEE ALSO
 
-rsa(3)
+L<rsa(3)|rsa(3)>
 
 =head1 HISTORY