working with logos

I'm very new to corel and i just finished designing a poster but i need to add logos. the problem i'm having is that they're in jpeg and they have a white background. i need to remove the white background. i've tried the magic wand and then going to mask and invert. the problem with this is that i can still see quite a bit of white around the logo. does anyone have any suggestions? maybe an easier way or do i need to go in and clean up the edges in photo paint's cut out lab? i can do this but it just seems like a lot of work and i have to work with about 15 logos, thanks.