Rath VL, et al. (1992) Purification and crystallization of glycogen phosphorylase from Saccharomyces cerevisiae. J Mol Biol 225(4):1027-34 PMID:1613787
Hwang PK and Fletterick RJ (1986) Convergent and divergent evolution of regulatory sites in eukaryotic phosphorylases. Nature 324(6092):80-4 PMID:3537803