Linkedin doesn't make it easy for you to search if you have Free or Premium package. You can often meet this message by Linkedin: "commercial use limit on search".
Here are some tools you can use to better find on Linkedin.
Linkedin often thinks this is the case: "you’re likely using LinkedIn for commercial use, like hiring or prospecting" and frankly, they are often correct. Yes, we try to pay less, or nothing and get the results. Sourcers and Business Development professionals are searching. Finding is their job. Am I correct?
My all time favourite tool is helping you to use Google's results. They call this Linkedin X-Ray, or simply inX and you can find them on Sourcehub by SocialTalent. As they say at SocialTalent: "that allows you to search LinkedIn extremely effectively WITHOUT LinkedIn registering that you’ve made a search and without using up your search quota."
with free Linkedin account you can use Sourcehub, and Linkedin won't recognise it, otherwise you can do 3 profile searches
you can search on many more platforms such as Github, Behance, About.me
Did you know that Linkedin's "professional accounts, such as Sales Navigator, Lite, and LinkedIn Recruiter, provide "pseudo-Boolean" search features that are not intuitive and may lead you to miss desired candidates". I have read this on one of Linkedin's best hacker or knower Irina Shamaeva's website.
SocialList.io a searching solution
This searching tool is Irina's, called Sociallist. This is what they are really good at:
finding all the listed email address of the search results (either one by one, or all the results')
You can search and find on these tools not available on SocialTalent: Researchgate, Meetup.com, Google Scholar
Ask me about Linkedin! Tamas Banki email@example.com +36709328054