Place entries without a date at the end of a chronological bibliography

Question

I'm using BibTeX with the plainyr style. I'm referencing some websites, but these of course don't have a date. I would like them to be placed at the end of my bibliography and not at the start (as is currently the case).

When running BibTeX I get the following warning:

Warning--to sort, need year or key in siteA

This suggests that I might add some key to influence sorting, but I don't know how this should be done. Adding a year seems wrong to me.

Here is how such a site entry looks like in my database:

@MISC{siteA,
  title = {http://www.site.com},
  owner = {nvcleemp},
  timestamp = {2012.04.06}
}

Answer 1

The field to add the key is just named key. If I just had tried some things I guess it would have been the first I tried, but I wanted certainty before trying. So this is how the entry in my database now looks:

@MISC{siteA,
  title = {http://www.site.com},
  key = {a},
  owner = {nvcleemp},
  timestamp = {2012.04.06}
}