This system is still under trial.
If you notice any problem with it, please, let us know: send an email to
p_erdos@renyi.hu

If you have a better version of our pdf files, also, please, send it to us. Our policy is to post first always the original version and then (if your one is better than our one not only because it is a better scanned in version but because it is a retyped one or produced from the original text in some other way, we would post it as a second version if it is noticably better than ours.

If you have a relevant remark on these papers, please, inform us about it and we shall consider if to post it.

Editors