Citation: D. Wheeler, A GEL-CONCENTRATION-INDEPENDENT RETARDATION DETECTED IN 2 FRAGMENTS OF THE RRNB P1 PROMOTER OF ESCHERICHIA-COLI USING TRANSVERSE POLYACRYLAMIDE PORE GRADIENT GEL-ELECTROPHORESIS, Biochemical and biophysical research communications, 193(1), 1993, pp. 413-419