Fix typos in documentation

Change-Id: I748c9c3d6cd1c5906daa9f68aea92d8ad536bf3b

docs/source/nnls_solving.rst

diff --git a/docs/source/nnls_solving.rst b/docs/source/nnls_solving.rst
index 00e1e3e..e281b28 100644
--- a/docs/source/nnls_solving.rst
+++ b/docs/source/nnls_solving.rst
@@ -1935,7 +1935,7 @@
 
    Size of the trust region at the end of the current iteration. For
    the Levenberg-Marquardt algorithm, the regularization parameter is
-   1.0 / member::`IterationSummary::trust_region_radius`.
+   1.0 / :member:`IterationSummary::trust_region_radius`.
 
 .. member:: double IterationSummary::eta
 

docs/source/nnls_tutorial.rst

diff --git a/docs/source/nnls_tutorial.rst b/docs/source/nnls_tutorial.rst
index b5f2710..ba68a78 100644
--- a/docs/source/nnls_tutorial.rst
+++ b/docs/source/nnls_tutorial.rst
@@ -890,7 +890,7 @@
    :math:`[-\pi,\pi)`.  Specially, we define the
    :member:`AngleManifold::Plus()` function to be:
    :math:`\mathrm{Normalize}(\psi + \Delta)` and
-   ::member::`AngleManifold::Minus()` function to be
+   :member:`AngleManifold::Minus()` function to be
    :math:`\mathrm{Normalize}(y) - \mathrm{Normalize}(x)`.
 
    This package includes an executable :member:`pose_graph_2d` that will read a