Bruno Becker Paolo Giulio Franciosa Stephan Gschwind Thomas Ohler Gerald Thiemt Peter Widmayer Enclosing Many Boxes by an Optimal Pair of Boxes. 475-486 1992 conf/stacs/1992 STACS db/conf/stacs/stacs92.html#BeckerFGOTW92 http://dx.doi.org/10.1007/3-540-55210-3_206