I found the study: http://www.sciencedirect.com/science/article/pii/0164121285900068 http://www.sciencedirect.com/science/article/pii/01641212859... Jeffrey,

I found the study: http://www.sciencedirect.com/science/article/pii/0164121285900068 http://www.sciencedirect.com/science/article/pii/01641212859... Jeffrey, D.R. and M.J. Lawrence, "Managing Programming Productivity", The Journal of Systems and Software 5, (1985), 49-58.