Updated citing info

doc/about.md

@@ -6,15 +6,32 @@
 * Kai Sun, University of Tennessee, Knoxville <<kaisun@utk.edu>>
 * Jianzhe Liu, Argonne National Laboratory <<jianzhe.liu@ieee.org>>
 
+### Citing
+
+If you are using **PowerSAS.m** in research work to be published, please include explicit citation of our work in your publication. Please place the following entries in your bibliography:
+
+[1]. J. Liu, R. Yao, F. Qiu, Y. Liu and K. Sun, "PowerSAS.m – An Open-Source Power System Simulation Toolbox Based on Semi-Analytical Solution Technologies," in IEEE Open Access Journal of Power and Energy, doi: 10.1109/OAJPE.2023.3245040.
+
+The corresponding BiBTex citations are given below:
+
+    @ARTICLE{powersas,
+             author={Liu, Jianzhe and Yao, Rui and Qiu, Feng and Liu, Yang and Sun, Kai},
+             journal={IEEE Open Access Journal of Power and Energy}, 
+             title={PowerSAS.m – An Open-Source Power System Simulation Toolbox Based on Semi-Analytical Solution Technologies}, 
+             year={2023},
+             doi={10.1109/OAJPE.2023.3245040}
+            }
+
 ### Acknowledgement
 This work is supported by the Laboratory Directed Research and Development (LDRD) program of Argonne National Laboratory, provided by the U.S. Department of Energy Office of Science under Contract No. DE-AC02-06CH11357, and the U.S. Department of Energy Office of Electricity, Advanced Grid Modeling program under Grant DE-OE0000875.
 
 ### Publications
-* Rui Yao, Kai Sun, Feng Qiu, “Vectorized Efficient Computation of Padé Approximation for Semi-Analytical Simulation of Large-Scale Power Systems,” IEEE Transactions on Power Systems, 34 (5), 3957-3959, 2019.
-* Rui Yao, Yang Liu, Kai Sun, Feng Qiu, Jianhui Wang,"Efficient and Robust Dynamic Simulation of Power Systems with Holomorphic Embedding", IEEE Transactions on Power Systems, 35 (2), 938 - 949, 2020.
-* Rui Yao, Feng Qiu, "Novel AC Distribution Factor for Efficient Outage Analysis", IEEE Transactions on Power Systems, 35 (6), 4960-4963, 2020.
-* Xin Xu, Rui Yao, Kai Sun, Feng Qiu, "A Semi-Analytical Solution Approach for Solving Constant-Coefficient First-Order Partial Differential Equations", IEEE Control Systems Letters, 6, 704-709, 2021.
-* Rui Yao, Feng Qiu, Kai Sun, “Contingency Analysis Based on Partitioned and Parallel Holomorphic Embedding”, IEEE Transactions on Power Systems, in press.
+* Jianzhe Liu, Rui Yao, Feng Qiu, Yang Liu and Kai Sun, "PowerSAS.m – An Open-Source Power System Simulation Toolbox Based on Semi-Analytical Solution Technologies," in IEEE Open Access Journal of Power and Energy, 2023.
+* Rui Yao, Kai Sun and Feng Qiu, “Vectorized Efficient Computation of Padé Approximation for Semi-Analytical Simulation of Large-Scale Power Systems,” IEEE Transactions on Power Systems, 34 (5), 3957-3959, 2019.
+* Rui Yao, Yang Liu, Kai Sun and Feng Qiu, Jianhui Wang,"Efficient and Robust Dynamic Simulation of Power Systems with Holomorphic Embedding", IEEE Transactions on Power Systems, 35 (2), 938 - 949, 2020.
+* Rui Yao and Feng Qiu, "Novel AC Distribution Factor for Efficient Outage Analysis", IEEE Transactions on Power Systems, 35 (6), 4960-4963, 2020.
+* Xin Xu, Rui Yao, Kai Sun and Feng Qiu, "A Semi-Analytical Solution Approach for Solving Constant-Coefficient First-Order Partial Differential Equations", IEEE Control Systems Letters, 6, 704-709, 2021.
+* Rui Yao, Feng Qiu and Kai Sun, “Contingency Analysis Based on Partitioned and Parallel Holomorphic Embedding”, IEEE Transactions on Power Systems, 2022.
 
 ### License
 This software is under BSD license. Please refer to LICENSE.md for details.