DOC: remove unimplemented :doi: role from dct docstring
@@ -358,8 +358,8 @@ def dct(x, type=2, n=None, axis=-1, norm=None, overwrite_x=False):
----------
.. [1] 'A Fast Cosine Transform in One and Two Dimensions', by J.
Makhoul, `IEEE Transactions on acoustics, speech and signal
- processing` vol. 28(1), pp. 27-34,
- :doi:`10.1109/TASSP.1980.1163351` (1980).
+ processing` vol. 28(1), pp. 27-34, 1980.
+ https://doi.org/10.1109/TASSP.1980.1163351
.. [2] Wikipedia, "Discrete cosine transform",
https://en.wikipedia.org/wiki/Discrete_cosine_transform
