Cite page of paper vs page of proceedings
Page numbers are largely irrelevant. There are not so many dead tree copies around, and a digital copy may be modified. In that case, searching for the title on it is trivial. You are providing the DOI, that is a permanent identificator, so you don't have to worry about it.

On a practical thing, I just use DOI's API to get the citations, and leave them worry about the details:

[david@LCARS david]$ curl -LH "Accept: text/bibliography; style=bibtex" http://dx.doi.org/10.1007/11678564_15


That gives you:


  @article{Rozinat_2006, title={Conformance Testing: Measuring the Fit and Appropriateness of Event Logs and Process Models}, ISBN={http://id.crossref.org/isbn/978-3-540-32596-3}, ISSN={1611-3349}, url={http://dx.doi.org/10.1007/11678564_15}, DOI={10.1007/11678564_15}, journal={Lecture Notes in Computer Science}, publisher={Springer Science + Business Media}, author={Rozinat, A. and der Aalst, W. M. P.}, year={2006}, pages={163–176}}


It is easy, fast to generate if you have the DOI, and minimises the risk of typos.