1. European Directorate for the Quality of Medicines and Healthcare (EDQM): European Pharmacopeia 6(8). Chapter 2.9.40. Uniformity of dosage units. Strasbourg: Council of Europe; 2010.
2. European Directorate for the Quality of Medicines and Healthcare (EDQM): European Pharmacopeia 6(8). Chapter 2.9.18. Preparations for inhalations: aerodynamic assessment of fine particles. Strasbourg: Council of Europe; 2010.
3. European Directorate for the Quality of Medicines and Healthcare (EDQM): European Pharmacopeia 6(8). Chapter 2.9.44. Preparations for nebulisation. Strasbourg: Council of Europe; 2010.
4. US Pharmacopeial Convention. United States Pharmacopeia; USP 37-NF 32; Chapter 601 – Physical tests and determinations: Aerosols. Rockville, MD, USA; 2014.
5. US Pharmacopeial Convention. United States Pharmacopeia; USP 37-NF 32; Chapter 1601 – Products for nebulization. Rockville, MD, USA; 2014.