@article{DBLP:journals/siamcomp/HopcroftU73,
author = {John E. Hopcroft and
Jeffrey D. Ullman},
title = {Set Merging Algorithms},
journal = {SIAM J. Comput.},
volume = {2},
number = {4},
year = {1973},
pages = {294-303},
ee = {http://dx.doi.org/10.1137/0202024},
bibsource = {DBLP, http://dblp.uni-trier.de}
}