How do I find owners phone numbers?

[Robert Wesner]

My wife and I are newbie investors in central-northern New Jersey looking to start out by wholesaling properties. We are getting numerous leads from several outside sales professionals that are on the road and driving by vacant properties. We then research them to verify that they are not yet on market anywhere, then we can usually find the owner’s names by public record. Where we’re having difficulties is in getting in touch with these owners and we are looking for suggestions as to the most cost-effective method of tracking down phone numbers for these absentee owners? Any help or suggestions would be greatly appreciated!