Noisy Independent Component Analysis as a Method of Rotating the Factor Scores. - Steffen Unkel; Nickolay T. Trendafilov (ICA, 2007)

Factor Analysis as Data Matrix Decomposition: A New Approach for Quasi-Sphering in Noisy ICA. - Steffen Unkel; Nickolay T. Trendafilov (ICA, 2009)

Factor Analysis of Data Matrices : New Theoretical and Computational Aspects with Applications. - Steffen Unkel (2009)

A majorization algorithm for simultaneous parameter estimation in robust exploratory factor analysis. - Steffen Unkel; Nickolay T. Trendafilov (Comput. Stat. Data Anal., 2010)

Zig-zag exploratory factor analysis with more variables than observations. - Steffen Unkel; Nickolay T. Trendafilov (Comput. Stat., 2013)

Exploratory factor and principal component analyses: some new aspects. - Nickolay T. Trendafilov; Steffen Unkel; Wojtek J. Krzanowski (Stat. Comput., 2013)