Q: Are there any differences between a print journal and an electronic one?

A: Yes, often there are differences. Electronic versions of journals or books are not necessarily 100% the same as print versions.

Sometimes electronic versions have more material, since they don't have the same space or presentation restrictions as print. Often authors will include supplemental data files or images to supplement an article that appeared in print.

Sometimes the e-versions have less material than the print. For example, some journals only include the actual articles, while leaving out job ads, product ads, notices, and so on.

When a database links to full-text articles, the database may only index the journal selectively; that is, the database may not include every article published in a particular journal.