@article{GDZPPN00219824X,
title = {Ergodic theorems for superadditive processes.},
journal = {Journal f\"ur die reine und angewandte Mathematik},
volume = {329},
year = {1981},
pages = {53-67},
zbl = {0453.60039},
url = {http://dml.mathdoc.fr/item/GDZPPN00219824X}
}
Krengel, U.; Akcoglu, M.A. Ergodic theorems for superadditive processes.. Journal für die reine und angewandte Mathematik, Tome 329 (1981) pp. 53-67. http://gdmltest.u-ga.fr/item/GDZPPN00219824X/