I did, go see that page, there is nothing there! Only 1 tut and it is deleted!
As you see the update of the text says it will be updated soon. Sorry to say i didn't know that, meanwhile you could head into the filterscript section and look for business filterscripts, analyze them and try out for yourself. You should get the hang of it. ( that's how i learnt it ), though i read a vehicle ownership tutorial instead. Later i wrote one, then created a business system. It's not that hard if you try hard enough.