Calling problem dogs

[MatthewKoelling]

So I have been shooting problem coyotes for a guy that runs a large sheep operation. I haven't been calling them and haven't honestly even tried because he said he never had any luck trying to call them.
I've killed about 25 of them just waiting for them to come in over the last couple months, or walking in to the dead pile. Anyway I was wondering what sounds work well when they are already focused on a mission.

 

[Kwarw1]

I usually start with a lonesome female howl 2-3 then shut up. I wait around 15 minutes before I give it one or two more I call very little. They usually come looking around trying to find the new girl. There are a lot of strategies and a lot depends on time of year too.