Add missing ref

Author: tsbinns

paper/paper.bib

@@ -143,6 +143,18 @@ @inproceedings{Lam2015
   doi={10.1145/2833157.2833162}
 }
 
+@article{Nikias1987,
+  title={Bispectrum estimation: {A} digital signal processing framework},
+  author={Nikias, Chrysostomos L. and Raghuveer, Mysore R.},
+  journal={Proceedings of the IEEE},
+  volume={75},
+  number={7},
+  pages={869--891},
+  year={1987},
+  publisher={IEEE},
+  doi={10.1109/PROC.1987.13824}
+}
+
 @article{Nikias1988,
   title={Time delay estimation in unknown {G}aussian spatially correlated noise},
   author={Nikias, Chrysostomos L. and Pan, Renlong},