Endoscopic ultrasound-guided fine-needle aspiration vs fine-needle biopsy for the diagnosis of pancreatic neuroendocrine tumors oleh Leonardo H. Eusebi, Douglas Thorburn, Christos Toumpanakis, Leonardo Frazzoni, Gavin Johnson, Sheida Vessal, Tu Vinh Luong, Martyn Caplin, Stephen P. Pereira