README.md: fix typos and broken links

README.md

@@ -16,7 +16,7 @@ code. It also happens that I was familiar with Cython.
 
 It took me a couple of hours to figure out how to get this to work
 properly, and with no real tutorial or simple advice to follow, I made
-(a starter kit)[https://version.helsinki.fi/weir/cython-and-scipy]
+[a starter kit](https://version.helsinki.fi/weir/cython-and-scipy)
 showing a minimal working example.
 
 Note that I don't fully know all the jargon names given to bits of
@@ -41,10 +41,10 @@ The starter kit contains the following files:
     basics](https://cython.readthedocs.io/en/latest/src/userguide/language_basics.html)
     for an explanation of what `cdef` is). We want to turn this into
     C, compile it, and then later on use it to instantiate a
-    `[scipy.LowLevelCallable](https://docs.scipy.org/doc/scipy/reference/generated/scipy.LowLevelCallable.html)`
+    [`scipy.LowLevelCallable`](https://docs.scipy.org/doc/scipy/reference/generated/scipy.LowLevelCallable.html)
     instance so `scipy.integrate` can use that rather than working
     with interpreted python (which is slow).
-
+	
 -   `test.pxd` is a Cython "header" file (I don't know what the
     correct name is, but the [Cython
     documentation](https://cython.readthedocs.io/en/latest/src/tutorial/pxd_files.html)
@@ -58,13 +58,19 @@ The starter kit contains the following files:
     The corresponding python module then has the attribute
     `__pyx_capi__`, which is also needed for
     `LowLevelCallable.from_cython()` to work. To be honest, I couldn't
-    find useful documentationa bout this, but I think this means that
-    it has a 'parallel' C interface, as it were
-    [this](https://github.com/ashwinvis/cython_capi/tree/master/using_pxd)
-    subdirectory of a repo by Ashwin Vishnu was useful.
+    find useful documentation about this, but I think this means that
+    it has a 'parallel' C interface, as it were.
+
+    [This](https://github.com/ashwinvis/cython_capi/tree/master/using_pxd)
+    subdirectory of a repo by Ashwin Vishnu was useful, as was [this
+    article](http://pdebuyl.be/blog/2017/cython-module.html) by Pierre
+    de Buyl.
 
 -   `setup.py` is the usual distutils thing, but it knows it's
-    building a Cython module because of the call to `cythonize()`.
+    building a Cython module because of the call to `cythonize()` and
+    thus detects the `.pxd` file (there is otherwise no relationship
+    between them, no `cimport` or similar); I'm not entirely
+    sure, though.
 
 -   `run.py` uses the `integrand()` function from `test.pyx` to do
     some numerical integrals.
@@ -96,7 +102,7 @@ To try this out you will need: python 3, cython
         Should be 21.333...: 21.3333
 
     Uses
-    `[scipy.integrate.quad()](https://docs.scipy.org/doc/scipy/reference/generated/scipy.integrate.quad.html#scipy.integrate.quad)`
+    [`scipy.integrate.quad()`](https://docs.scipy.org/doc/scipy/reference/generated/scipy.integrate.quad.html#scipy.integrate.quad)
     to evaluate three numerical integrals. Note that I've tried to
     make it clear how to pass numerical coefficients from the python
     to the C code, so things don't need to be hardcoded.