fixed link

Author: kwinkunks

README.md

@@ -24,7 +24,7 @@ For more in-depth hints on getting started, see Hall, M (2016). A user guide to
 - [Other Notebooks](https://github.com/seg/tutorials-2018/tree/master/1806_Time-frequency)
 
 ## August 2018
-- [Neural networks]() by Graham Ganssle
+- [Neural networks](https://library.seg.org/doi/abs/10.1190/tle37080616.1) by Graham Ganssle
 - [Manuscript as Jupyter Notebook](https://github.com/seg/tutorials-2018/blob/master/1808_Neural_networks/Manuscript.ipynb)
 
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