Gottlob, G., Leone, N., & Scarcello, F. (1997). On the Complexity of Some Inductive Logic Programming Problems. Springer.

Gottlob, G., N. Leone, and F. Scarcello. On the Complexity of Some Inductive Logic Programming Problems. Springer, 1997.

Gottlob, G., et al. On the Complexity of Some Inductive Logic Programming Problems. Springer, 1997.