%% -*-BibTeX-*- @Article{GroetschelHolland1991, author = "Martin Gr{\"o}tschel and Olaf Holland", title = "Solution of large-scale symmetric travelling salesman problems", journal = "Mathematical Programming, Series A", volume = "51", number = "2", pages = "141--202", year = "1991", classmath = "*90C10 90C06 52B12 90-08 90C35 65K05", language = "English", }