@incollection{HanMla98a,
	author = "P. Hansen and N. Mladenovi\'c",
	title = "An introduction to variable neighborhood search",
        booktitle = "Meta-heuristics, {A}dvances and trends in
                      local search paradigms for optimization",
        editor = "S. Voss and S. Martello and I. H. Osman and C. Roucairol",
        publisher = "Kluwer Academic Publishers",
        city = "Dordrecht",
        pages = "433--458",
        year = "1998",
        annote =     	"This paper introduces the metaheuristic variable 
			neighborhood search. 
			This local search method expands the neighborhood
                	each time a local optimal solution is reached.  Once an
                	improvement is made, the search restarts at the
                	initial (smallest) neighborhood.  The search ends once
                	a local optimum of the largest neighborhood is found."
}

@Article{HarSho87a,
	author = "J.P. Hart and A.W. Shogan",
	title = "Semi-greedy heuristics: {A}n empirical study",
	journal = "Operations Research Letters",
	volume = "6",
	pages = "107--114",
	year = "1987",
        annote   = "In this paper the authors present a general heuristic
                    schema, called semi-greedy heuristic which, in contrast
                    to the greedy schema, uses randomization within the
                    heuristic in the following two possible ways: given
                    $p$ or $c$, a semi-greedy heuristic randomly chooses
                    each iteration decision from among those decisions
                    resulting in bjective improvements either within
                    $p\%$ of the best improvement or among the $c$ best
                    improvements.",
}