Complex sentence: In the years after they were first established, Blacky pictures were used by various researchers, the most prominent of whom may have been Blum and Kaufman Blum, G. S., & Kaufman, J. B. (1952).
Split into simpler sentences: In the years after they were first established, Blacky pictures were used by various researchers. The most prominent of these may be Blum and Kaufman, Blum, G. S., & Kaufman, J. B. (1952).