Hoog, C., Calzone, F. J., Cutting, A. E., Britten, R. J. and Davidson, E. H. (1991). Gene regulatory factors of the sea urchin embryo. II. Two dissimilar proteins, P3A1 and P3A2, bind to the same target sites that are required for early territorial gene expression. Development 112 (1): 351-364
Zeller, R. W., Britten, R. J. and Davidson, E. H. (1995). Developmental utilization of SpP3A1 and SpP3A2: two proteins which recognize the same DNA target site in several sea urchin gene regulatory regions. Dev. Biol. 170 (1): 75-82