This link is to the meta-analysis done by Brotman and Moore. And the citation for their paper:
Brotman, J.S. & Moore, F.M. (2008). Girls and science: A review of four themes in the science education literature. Journal of Research in Science Teaching, 45(9), 971-1002.
If you are at all interested in pursuing more information on the research and literature on science education and gender... their list of references is extensive... they've done the leg-work through 2008. Enjoy.