Subclassification of the “Grey Zone” of Thyroid Cytology; A Retrospective Descriptive Study with Clinical, Cytological, and Histological Correlation oleh Mariella Bonzanini, Pierluigi Amadori, Luca Morelli, Silvia Fasanella, Riccardo Pertile, Angela Mattiuzzi, Giorgio Marini, Mauro Niccolini, Giuseppe Tirone, Marco Rigamonti, Paolo Dalla Palma