http://doi.acm.org/10.1145/984488.984493 Ramez Elmasri Cory Devor Said K. Rahimi Notes of DDTS - An Apparatus for Experimental Research in Distributed Database Management Systems. 32-49 sigmodR/11-4/P032.pdf 1981 11 SIGMOD Record 4 db/journals/sigmod/sigmod11.html#ElmasriDR81