In my scipy-style docstring I have:
..., see :ref:`notes <filt_int_notes>`.
Other text.
.. _filt_int_notes:
Notes
-----
Some cool notes.
According to Adding a cross-reference to a subheading or anchor in another page and http://sphinx-doc.org/markup/inline.html#role-ref.
But the ref doesn't generate a link!
My docstrings are generated with autosummary.