diff --git a/README.md b/README.md
index 49131ec..05defe2 100644
--- a/README.md
+++ b/README.md
@@ -14,22 +14,24 @@ There will be 2 deliverables from this folder:
 
 It contains a few supporting files, notably:
 
-- `tests.sql` for synthetic unit tests.
-- `test-rivers.sql` for tests with real rivers.
-- `Makefile` to glue everything together.
+- `tests.sql` synthetic unit tests.
+- `test-rivers.sql` tests with real rivers.
+- `Makefile` glues everything together.
 - `layer2img.py` converts a PostGIS layer to an embeddable image.
+- `aggregate-rivers.sql` combines multiple river objects (linestrings or
+  multilinestrings) to a single one.
 - `init.sql` initializes PostGIS database for running the tests.
 - `rivers.sql` is an OpenStreetMap snapshot of select rivers (`Makefile`
   contains code to update them).
-- ... and a few more files to build the paper.
+- ... and a few more files necessary to build the paper.
 
-Running it
-----------
+Running
+-------
 
-`make help` lists the most interesting commands for humans. As of writing:
+`make help` lists the select commands for humans. As of writing:
 
 ```
-$ make help
+# make help
 mj-msc-full.pdf    Thesis for publishing
 test               Unit tests (fast)
 test-rivers        Rivers tests (slow)
@@ -59,6 +61,17 @@ published. It needs quite a few dependencies, including a functioning Docker
 environment, postgresql client, geopandas, and a pretty complete LaTeX
 installation.
 
+Contributing
+------------
+
+Please reach out to me before contributing. As of writing, this is not ready to
+accept broader contributions, TODO:
+
+[ ] CI.
+[ ] It has a bug in `wm_self_crossing`: the program crashes with a river in
+    Lithuania.
+[ ] Implementation is not yet complete (stay tuned).
+
 License
 -------
 
diff --git a/wm.sql b/wm.sql
index c5135da..5cc0071 100644
--- a/wm.sql
+++ b/wm.sql
@@ -281,7 +281,7 @@ begin
   for i in 1..array_length(bends, 1) loop
     continue when abs(wm_inflection_angle(bends[i])) <= pi;
     -- sum of inflection angles for this bend is >180, so it may be
-    -- self-crossing. now try to find another bend in this line that
+    -- self-crossing. Now try to find another bend in this line that
     -- crosses an imaginary line of end-vertices
 
     -- Go through each bend in the given line, and see if has a potential to