The original data set is available in the multilevel
package and was altered by (a) transforming workload into a categorical variable, (b) transforming cohesion into a group-level variable, and (c) by inducing missing values.
data(leadership)
Bliese, P. D. (2013). multilevel: Multilevel functions (Version 2.5) [Computer software]. Retrieved from http://CRAN.R-project.org/package=multilevel
Klein, K. J., Bliese, P. D., Kozlowski, S. W. J., Dansereau, F., Gavin, M. B., Griffin, M. A., ... Bligh, M. C. (2000). Multilevel analytical techniques: Commonalities, differences, and continuing questions. In K. J. Klein & S. W. J. Kozlowski (Eds.), Multilevel theory, research, and methods in organizations: Foundations, extensions, and new directions (pp. 512-553). San Francisco, CA: Jossey-Bass.