@book{
title = {Corso elementare ed intermedio },
author = {Katerinov, Katerin},
editor = {Boriosi Katerinov, Maria Clotilde},
editor = {998014355308896 - La lingua italiana per stranieri -  },
year = {1985},
edition = {4. ed},
address = {Perugia },
publisher = {Guerra},
}