diff --git a/README.md b/README.md
index 0e300e3..8bb584f 100644
--- a/README.md
+++ b/README.md
@@ -694,7 +694,7 @@ echo 'Please reopen the shell to activate completion.'
 
 Find some contributor instructions in [DEVELOPER.md](docs/DEVELOPER.md).
 
-#### AWK
+### AWK
 
 The core of this tool is implemented in [AWK](https://en.wikipedia.org/wiki/AWK).
 Almost all major implementations of AWK will work. Tested and officially supported are [Gawk](https://www.gnu.org/software/gawk/), [BWK](https://github.com/onetrueawk/awk), [mawk](https://invisible-island.net/mawk/). This means that the default AWK implementation in your OS will work.
diff --git a/mdbooker.awk b/mdbooker.awk
index f7f82eb..fa87341 100644
--- a/mdbooker.awk
+++ b/mdbooker.awk
@@ -2,6 +2,7 @@ BEGIN {
   OUTDIR = "book"
   SUMMARY = OUTDIR "/SUMMARY.md"
   printf "" > SUMMARY
+  N = 0
   H = 0
   Title = ""
   Content = ""
@@ -15,13 +16,14 @@ BEGIN {
 
 function handleTitle(h,   md) {
   if (Title) {
-    md = Title ".md"
+    N++
+    md = (N < 10 ? "0": "") N "_" Title ".md"
     print "generating: " md "..."
-    print Content > md
+    print Content > OUTDIR "/" md
     printf "%" ((H - 1) * 4) "s%s[%s](%s)\n", "", 1 == H ? "" : "-", Title, md >> SUMMARY
   }
   H = h
-  Title = trim(substr($0, h))
+  Title = trim(substr($0, h+1))
   Content = ""
 }