diff --git a/atomic_factors.c b/atomic_factors.c
deleted file mode 100644
index c009f658e6d5eb465e8cf07a93a73dfbcb5b3543..0000000000000000000000000000000000000000
--- a/atomic_factors.c
+++ /dev/null
@@ -1,36 +0,0 @@
-#include <omp.h>
-#include <stdio.h>
-#include <stdlib.h> //malloc
-#include <string.h> //memset
-
-#include "openmp_getmax.c"
-
-int main(){
-    long int max = 1e7;
-    int *factor_ct = malloc(sizeof(int)*max);
-
-    factor_ct[0] = 0;
-    factor_ct[1] = 1;
-    for (long int i=2; i< max; i++)
-        factor_ct[i] = 2;
-
-    #pragma omp parallel for
-    for (long int i=2; i<= max/2; i++)
-        for (long int scale=2; scale*i < max; scale++) {
-                #pragma omp atomic update
-                factor_ct[scale*i]++;
-            }
-
-    int max_factors = get_max_factors(factor_ct, max);
-    long int tally[max_factors+1];
-    memset(tally, 0, sizeof(long int)*(max_factors+1));
-
-    #pragma omp parallel for
-    for (long int i=0; i< max; i++){
-        #pragma omp atomic update
-        tally[factor_ct[i]]++;
-    }
-
-    for (int i=0; i<=max_factors; i++)
-        printf("%i\t%li\n", i, tally[i]);
-}
diff --git a/openmp_getmax.c b/openmp_getmax.c
index edcf2f475ce1c8e47d3c9ceb0a6e1db8f2c494ea..6b17d9c13392f2a90b8f847296bf6986f6e83b66 100644
--- a/openmp_getmax.c
+++ b/openmp_getmax.c
@@ -1,3 +1,5 @@
+/* See compilation notes in atomic_factors.c, openmp_atoms.c, or pthread_factors.c*/
+
 int get_max(int *array, long int max){
     int thread_ct = omp_get_max_threads();
     int maxes[thread_ct];
diff --git a/strtod.c b/strtod.c
index 36ae3e8ca3f322b8acc785d29225aaf9244f7997..1a9d5a942b80bcf4bd9ec84e2c6cd69513e349ee 100644
--- a/strtod.c
+++ b/strtod.c
@@ -1,3 +1,7 @@
+/* Compile with:
+export CFLAGS="-g -Wall -std=gnu11 -O3"  #the usual.
+make strtod
+*/
 #include "stopif.h"
 #include <stdlib.h> //strtod
 #include <math.h>   //pow
diff --git a/times_table.c b/times_table.c
index ae5fba427d8f39f372d0b3b08bfc8afb710bd797..7a66adcff96f0ef9bf59a4ac621b4bd94fa8c442 100644
--- a/times_table.c
+++ b/times_table.c
@@ -1,3 +1,7 @@
+/* Compile with:
+export CFLAGS="-g -Wall -std=gnu11 -O3"  #the usual.
+make times_table
+*/
 #include <math.h> //NAN
 #include <stdio.h>