Günter Mahler Ilki Kim Correlation between Correlations: Process and Time in Quantum Networks. 89-102 1998 conf/qcqc/1998 QCQC http://link.springer.de/link/service/series/0558/bibs/1509/15090089.htm db/conf/qcqc/qcqc1998.html#MahlerK98