[1] Moses, R.L. and Liu, D. (1991) Optimal Nonnegative Definite Approximation of Estimated Moving Average Covariance Sequences. IEEE Transactions on Signal Processing, 39, 2007-2015.
http://dx.doi.org/10.1109/78.134433
[2] Qian, G. and Zhao, X. (2007) On Time Series Model Selection Involving Many Candidate ARMA Models. Computational Statistics and Data Analysis, 51, 6180-6196.
http://dx.doi.org/10.1016/j.csda.2006.12.044
[3] Li, Z.Y. and Li, D.G. (2008) Strong Approximation for Moving Average Processes under Dependence Assumptions. Acta Mathematica Scientia, 28, 217-224.
http://dx.doi.org/10.1016/S0252-9602(08)60023-5
[4] Box, G.E.P., Jenkins, G.M. and Reinsel, G.C. (1994) Time Series Analysis: Forecasting and Control. 3rd Edition, Prentice-Hall, Englewood Cliffs.
[5] Okereke, O.E., Iwueze, I.S. and Johnson, O. (2013) Extrema of Autocorrelation Coefficients for Moving Average Processes of Order Two. Far East Journal of Theoretical Statistics, 42, 137-150.
[6] Al-Marshadi, A.H. (2012) Improving the Order Selection of Moving Average Time Series Model. African Journal of Mathematics and Computer Science Research, 5, 102-106.
[7] Adewumi, M. (2014) Solution Techniques for Cubic Expressions and Root Finding. Courseware Module, Pennsylvania State University, Pennsylvania.
[8] Okereke, O.E., Iwueze, I.S. and Johnson, O. (2014) Some Contributions to the Solution of Cubic Equations. British Journal of Mathematics and Computer Science, 4, 2929-2941.
http://dx.doi.org/10.9734/BJMCS/2014/10934
[9] Wei, W.W.S. (2006) Time Series Analysis, Univariate and Multivariate Methods. 2nd Edition, Pearson Addision Wesley, New York.
[10] Chatfield, C. (1995) The Analysis of Time Series. 5th Edition, Chapman and Hall, London.
[11] Palma, W. and Zevallos, M. (2004) Analysis of the Correlation Structure of Square of Time Series. Journal of Time Series Analysis, 25, 529-550.
http://dx.doi.org/10.1111/j.1467-9892.2004.01797.x
[12] Iwueze, I.S. and Ohakwe, J. (2011) Covariance Analysis of the Squares of the Purely Diagonal Bilinear Time Series Models. Brazilian Journal of Probability and Statistics, 25, 90-98.
http://dx.doi.org/10.1214/09-BJPS111
[13] Iwueze, I.S. and Ohakwe, J. (2009) Penalties for Misclassification of First Order Bilinear and Linear Moving Average Time Series Processes.
http://interstatjournals.net/Year/2009/articles/0906003.pdf
[14] Okereke, O.E. and Iwueze, I.S. (2013) Region of Comparison for Second Order Moving Average and Pure Diagonal Bilinear Processes. International Journal of Applied Mathematics and Statistical Sciences, 2, 17-26.
[15] Montgomery, D.C., Jennings, C.L. and Kaluchi, M. (2008) Introduction to Time Series Analysis and Forecasting. John Wiley and Sons, New Jersey.
[16] Sittinger, B.D. (2010) The Second Derivative Test. www.faculty.csuci.edu/brian.sittinger/2nd_Derivtest.pdf