1. Fokkens W, Lund V, Mullol J, European Position Paper on Rhinosinusitis and Nasal Polyps group (2007) European position paper on rhinosinusitis and nasal polyps 2007. Rhinol Suppl 20:1–136
2. Johnson JT, Rosen CA, Bailey BJ (2014) Bailey’s head and neck surgery--otolaryngology. Wolters Kluwer Health/Lippincott Williams & Wilkins, Philadelphia, p 1 online resource (2 volumes)
3. Zhang Y, Gevaert E, Lou H, Wang X, Zhang L, Bachert C, Zhang N (2017) Chronic rhinosinusitis in Asia. J Allergy Clin Immunol 140:1230–1239
4. Bachert C, Gevaert P, Hellings P (2017) Biotherapeutics in chronic rhinosinusitis with and without nasal polyps. J Allergy Clin Immunol Pract
5. Claus B, Wagenmann M, Ulrich H, Claudia R (1997) IL-5 synthesis is upregulated in human nasal polyp tissue. J Allergy Clin Immunol 6(99):837–842