• If no publication date is available, use, n.d. (=no date) instead of the year.  
• To make it easier for the reader to identify and retrieve the source, include a description of the source within square brackets after the title.
• If the material is available online, also include a URL.

Basic format:

Author, A. (year). Title [Description]. Publisher. https://xxxx 

Organization. (year). Title [Description]. Publisher. https://xxxx

Reference example: 

European Space Agency. (2019). Space economy Creating value for Europe [Broschure]. https://space-economy.esa.int/storage/downloads/WfOXRmxW6NHPInigMuqs0tkylB8SloL1rMwFpvrR.pdf

Comment: In this case, the publisher is the same as the author and can therefore be omitted.  

In-text citation: 

• European Space Agency (2019)...
• (European Space Agency, 2019)