Key points are not available for this paper at this time.
Over 4000 differentially determined photoelectric BVRI observations and the resulting light curves are presented for 112 Cepheids accessible from northern hemisphere observatories. The internal precision of these data is better than ±0.01 mag, and the accuracy of transformation to the Johnson BVRI system is nearly as good.
Moffett et al. (Sun,) studied this question.