I see there are some papers/thesis which says TSP is solvable in $O(n)$ in bounded tree-width graphs and some of them implicitly refer to Cook and Seymour (not exact paper just said that they solve it), but I can't find any paper about it.
All the things I can find is branch-decomposition based algorithms with merging techniques, which are all heuristic (e.g very nice heuristic) but non of them are exact algorithm. Does anyone know the related papers for linear time solution? Or paper which says is impossible? or probably impossible? (any good news bad news, its not 3in1 question:).