References

The original article is

• Plebanski, On the separation of Einsteinian substructures, J. Math. Phys. 18, 2511 (1977)

An account of the general formalism is in

• R. Capovilla, T. Jacobson, J. Dell, L. Mason, Selfdual 2-forms and gravity Classical and Quantum Gravity 8, 41 (1991) .

A discussion of practical computations in this formalism is in

• Kirill Krasnov, Plebanski Formulation of General Relativity: A Practical Introduction (arXiv)