1. Levene H. (1960): p. 278–292. In: I. Olkin, S. Ghurye, W. Hoefding, W. Madow & H. Mann (Eds), Contributions to Probability and Statistics: Essays in Honor of Harold Hotelling. – Stanford
2. Zar J. H. (1996): Biostatistical analysis. – New Jersey, 662 pp