What information is mandatory depends on the applied reference style, e.g. APA6 oder Chicago Style. The reference style even sets the number of authors listed maximum in the reference. Most of the times, the journal/conference sets the reference style you have to apply.
Usually, the mandatory information for journal/conference papers includes:
- Author(s) name(s)
- Title
- Year
- Journal/Conference name
- Page number
- DOI
The only real option to shorten anything is to use the abbreviations of journals/conferences. But the applied referencyreference style might even prevent this trick.