Question about target audience

[SEO-Linker]

Please help me with some issue which is probably simple for someone but I may need some help with it.

I am doing link building for 3 big sites at the moment. I know what a good link is , what relevant site is , etc. etc. (I am doing this for about 3 years along with on-site SEO)

For first I need to say something about sites I am working with (we have a system which allows to find sites directly from search engines based on keywords search)

1. Patent site: Intellectual Property attorneys, Patent Agents (the USPTO
maintains a list of the people -- there are about 30,000. The EPO also
has a similar list, but most don't have email addresses), researchers,
inventors.

2. EDGAR site: Investors (professional and private).

3. NIH/MedLine site: Biology and medical researchers (there must be
tens or hundreds of thousands of these)

So far I have been trying to find web sites that are relevant. But have not been trying to find PEOPLE that are relevant.
Even if I have exhausted most of the web sites out there, there are
thousands and thousands of people that I have not contacted simply
because they were not associated with a web site. Although contacting these people might not result in a link, sometimes it might, and it is worth it just to let them know about the sites.

How can I find email addresses for these people? Or, can I find some
alternate way of reaching them (such as developing a list of all the
biology departments at universities around the world and asking them to let
their faculty members know about our MedLine site)?

Somebody has to have this information. There are directories of
people, professional societies/organizations (e.g.,
http://www.medicalresearchers.org/), mailing list vendors, publications
(for example, some of the big science magazine publishers probably have some
pretty good lists), etc.

The attorneys might not be too hard to find through a list vendor, but
I haven't found much on medical/biology researchers (which would also
include biology graduate students), inventors, or investors.

Any thoughts on how I might pursue getting information on these groups
of people?

I need to find at least tens of thousands site for each of 3 sites , but not directly relevant. So small audience don't suit me.

Any help will be appreciated.

Thanks in advance,
Alexander Vahrushev