David C. Schwartz and Charles R. Cantor (1984). “Separation of yeast chromosome-sized DNAs by pulsed field gradient gel electrophoresis”. Cell37 (1): 67-75. doi:10.1016/0092-8674(84)90301-5.
GF Carle, M Frank, and MV Olson (1986). “Electrophoretic separations of large DNA molecules by periodic inversion of the electric field”. Science232: 65-58. doi:10.1126/science.3952500.