1. P. A. Sweet, inElectromagnetic Phenomena in Cosmical Physics, edited by B. Lehnert (Cambridge University Press, New York, 1958), p. 123.
2. Sweet's mechanism for merging magnetic fields in conducting fluids
3. Magnetic reconnection via current sheets
4. H. E. Petschek, inAAS/NASA Symposium on the Physics of Solar Flares, edited by W. N. Hess (NASA, Washington, DC, 1964), p. 425.