How to stop duplicate form submissions?

Hi, I'm getting an abnormally high amount of duplicate form submissions for this form: https://form.jotform.com/60437675687167 

Here is why they are so weird.... they are usually submitted anywhere form 5 to 45 minutes apart from each other. Sometimes they have the exact same info. Sometimes they have differing information. It is happening so often, it seems strange that it would be the users filling it out twice and from different referral sources. Here are some example people who are duplicate submissions on this form:

Christina Carbonara

Mary Ellen Volpa

Paula Ortiz

Any ideas? Thank you!

Hello, 

Please try to add a Captcha to your field. Here's a guide that you can follow: https://www.jotform.com/help/205-How-to-Add-a-Captcha-Field

If you do not want a Captcha field on your form, you can try using the Unique Submission to your form. If you're interested in it, here's a guide on how to enable it on your form: https://www.jotform.com/help/64-How-to-Set-Unique-Submissions-on-a-Form

I hope this information helps. Let us know how many duplicates you got we can remove it from your account usage.

Thank you.