I have an old cassette tape or two on calling, if I can find them I'll mail them to you, just pm me your address. The cow & bull calls are easily made with your mouth. Some area's, the bulls respond more readily to bull calls, other area's they respond better to cow calls. A homemade or store-bought megaphone can help get your calls out there further, a guy up here makes one called a bull magnet, maybe you can find one online. An old scapula is good for banging and raking on trees to sound like a bull doing just that, but they do break easy if you do it right. I have a half of an empty plastic quart oil can, with a 2 1/2 foot long stick taped into the narrow/pour end for making antler scraping noises. Its a lot of fun !