Eagly, A. H., & Johannesen-Schmidt, M. C. (2001). The leadership styles of women and men. Journal of social issues, 57(4), 781-797.
Gerber, G. L. (1988). Leadership roles and the gender stereotype traits. Sex Roles, 18(11-12), 649-668.
Koch, S. C., Luft, R., & Kruse, L. (2005). Women and leadership–20 years later: a semantic connotation study. Social Science Information, 44(1), 9-39.
McCauslan, J. A., & Kleiner, B. H. (1992). Women and organisational leadership. Equal Opportunities International, 11(6), 12-15.
Lantara, A. N. F., Haming, M., Mus, A. R., & Alam, R. (2012). The Effect of Woman Leadership Style and Organizational Culture on Locus of Control, Work Achievement, and Work Satisfaction of Employee. Journal of Public Administration and Governance, 2(4), Pages-32.
I would suggest that you check out the following research studies located at the following links. The researchers include some excellent surveys on research of women in leadership roles.