There are a number of good books on split-plots. I will add my suggestion for the following papers:
Box, G.E.P., Stephen Jones (1992), “Split-plot designs for robust product experimentation”, Journal of Applied Statistics, Vol. 19, No. 1
Jones, Bradley, Christopher J. Nachtsheim (2009) “Split-Plot Designs: What, Why, and How”, Journal of Quality Technology, Vol. 41, No. 4, pp. 340-361
"All models are wrong, some are useful" G.E.P. Box