Are springs from any other car fit my Accord?

One of my rear springs has just broken and I found that my rear shock-absorbers and springs are not original. They were remade and adjusted from unknown parts of unknown cars. I want to replace them but parts for Honda is very expensive and scarce in my country. And i want to find the same parts from more common in my country car. (Mazda, Toyota, Audi, VW, Mercedes)

So, maybe somebody knows exact parameters of original springs (diameter, stiffness, length and so on) ?