fix links

Author: SvenKlaassen

doc/conf.py

@@ -274,6 +274,8 @@
     "https://doi.org/10.1097%2FEDE.0b013e3181f74493",
     # Valid DOI; Causes 403 Client Error: Forbidden for url:...
     "https://doi.org/10.3982/ECTA15732",
+    # Valid DOI; Causes 403 Client Error: Forbidden for url:...
+    "https://doi.org/10.1093/ectj/utab019"
 ]
 
 # To execute R code via jupyter-execute one needs to install the R kernel for jupyter

doc/examples/py_double_ml_lplr.ipynb

@@ -105,7 +105,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "Next, define the learners for the nuisance functions and fit the [LPLR Model](https://docs.doubleml.org/stable/guide/models.html#logistic-partial-linear-regression-lplr).\n",
+    "Next, define the learners for the nuisance functions and fit the [LPLR Model](https://docs.doubleml.org/stable/guide/models.html#partially-linear-models-plm).\n",
     "The correct type of learner (regressor or classifier) must be used for each nuisance function.\n",
     "\n",
     "- ``ml_M`` is a model of the outcome. Here, since the outcome is binary, we use a classifier.\n",