DOC: Remove reference to paper from quantile method kwarg

Apparently, sphinx does not resolve references to footnotes from
parameter descriptions.

Author: seberg

numpy/lib/function_base.py

@@ -3899,7 +3899,7 @@ def percentile(a,
         This parameter specifies the method to use for estimating the
         percentile.  There are many different methods, some unique to NumPy.
         See the notes for explanation.  The options aligning with the R types
-        and the H&F paper [1]_ are:
+        and the H&F paper are:
 
         * (H&F 1): 'inverted_cdf'
         * (H&F 2): 'averaged_inverted_cdf'
@@ -4178,7 +4178,7 @@ def quantile(a,
         This parameter specifies the method to use for estimating the
         quantile.  There are many different methods, some unique to NumPy.
         See the notes for explanation.  The options aligning with the R types
-        and the H&F paper [1]_ are:
+        and the H&F paper are:
 
         * (H&F 1): 'inverted_cdf'
         * (H&F 2): 'averaged_inverted_cdf'

numpy/lib/nanfunctions.py

@@ -1274,7 +1274,7 @@ def nanpercentile(
         This parameter specifies the method to use for estimating the
         percentile.  There are many different methods, some unique to NumPy.
         See the notes for explanation.  The options aligning with the R types
-        and the H&F paper [1]_ are:
+        and the H&F paper are:
 
         * (H&F 1): 'inverted_cdf'
         * (H&F 2): 'averaged_inverted_cdf'
@@ -1428,7 +1428,7 @@ def nanquantile(
         This parameter specifies the method to use for estimating the
         quantile.  There are many different methods, some unique to NumPy.
         See the notes for explanation.  The options aligning with the R types
-        and the H&F paper [1]_ are:
+        and the H&F paper are:
 
         * (H&F 1): 'inverted_cdf'
         * (H&F 2): 'averaged_inverted_cdf'