"That part of the business" is still a huge portfolio of product offerings in-and-around the scientific publishing space. If you cut one head of the hydra, another will just grow back in its place.

The company came to be so dominant because their strategy of vertical integration is effective and repeatable. Identify a market of valuable information; build tools to collect & collate that information; build tools for searching through the information; build tools for adding annotations or otherwise improving the value of the information; build tools to enable people to provide information directly through the platform.

They've basically repeated this pattern for science, medicine, legal, and insurance industries. So much so that it's really impossible to pry them out of a space because they get so tightly integrated that they actually become indistinguishable from the market.

I'm not favoring reed elsevier here, just pointing out that their dominance is very well established and isn't going to be easy to bring them down.