Update README.md

README.md

@@ -44,8 +44,8 @@ https://github.com/lemire/runningmaxmin from Daniel Lemire paper, and improvemen
 
 # References
 
-1. Alexey A. Bobtsov, Nikolay A. Nikolaev, Olga V. Slita, Alexander S. Borgul, Stanislav V. Aranovskiy: The New Algorithm of Sinusoidal Signal Frequency Estimation. 11th IFAC International Workshop on
-Adaptation and Learning in Control and Signal Processing, 2013
+1. Alexey A. Bobtsov, Nikolay A. Nikolaev, Olga V. Slita, Alexander S. Borgul, Stanislav V. Aranovskiy: The New Algorithm of Sinusoidal Signal Frequency Estimation. [11th IFAC International Workshop on
+Adaptation and Learning in Control and Signal Processing, 2013](https://www.sciencedirect.com/science/article/pii/S1474667016329421)
 
 2. Sharkh S. M., Hendijanizadeh2 M., Moshrefi-Torbati3 M., Abusara M. A.: A Novel Kalman Filter Based Technique for Calculating the Time History of Vertical Displacement of a Boat from Measured Acceleration, [Marine Engineering Frontiers Volume 2, 2014](https://www.researchgate.net/profile/Mehdi-Hendijanizadeh/publication/264713649_A_Novel_Kalman_Filter_Based_Technique_for_Calculating_the_Time_History_of_Vertical_Displacement_of_a_Boat_from_Measured_Acceleration/links/53ec88db0cf24f241f1584c5/A-Novel-Kalman-Filter-Based-Technique-for-Calculating-the-Time-History-of-Vertical-Displacement-of-a-Boat-from-Measured-Acceleration.pdf "Marine Engineering Frontiers Volume 2, 2014")