GENERALIZED KRAMERS METRIC Article HORSKY J., MITSKIEVITCH N.V. Classical and Quantum Gravity. Vol. 7. 1990. P. 1523-1527
KILLING VECTORS OF VACUUM SPACE TIMES AND ELECTROMAGNETIC FOUR POTENTIALS Article Horský J., Mitskievitch N.V. Czechoslovak Journal of Physics. Kluwer Academic Publishers. Vol. 39. 1989. P. 957-961