From: gwoegi@fmatbds01.tu-graz.ac.REMOVE.at (Gerhard J. Woeginger)
Newsgroups: sci.math
Subject: Re: Pyramidal tours
Date: Sun, 3 Jan 1999 19:04:43
Keywords: Pyramid tours for the TSP

In article <368FAFA4.2915FCC1@hkusua.hku.hk> Lui Yu Chung Stanley <h9617508@hkusua.hku.hk> writes:
>From: Lui Yu Chung Stanley <h9617508@hkusua.hku.hk>
>Subject: Pyramidal tours
>Date: Mon, 04 Jan 1999 01:57:56 +0800

>I want to know where can I have some look for the pyramidal tours.
>If possible, please quote their URLs.  Thanks

I guess that you mean pyramidal tours for the travelling salesman problem.
Here are two papers that contain lots of informations and references:

J.A.A. van der Veen, G. Sierksma, R. van Dal: Pyramidal tours and the TSP,
European Journal of Operations Research 52 (1991), 90-102.

R.E. Burkard, V.G. Deineko, R. van Dal, J.A.A. van der Veen, G.J. Woeginger:
Well-solvable special cases of the TSP: A survey, SIAM Reviews 40 (1998), 
496-546.
___________________________________________________________
Gerhard J. Woeginger  (gwoegi@opt.math.tu-graz.ac.at)