Cover Photo Lars Jensen
©2013–2019 Steven Schlicker
Permission is granted to copy, distribute and/or modify this document under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. The work may be used for free by any party so long as attribution is given to the author(s), the work and its derivatives are used in the spirit of “share and share alike”; no party may sell this work or any of its derivatives for profit. All trademarks™ are the registered® marks of their respective owners. The graphic
creativecommons.org/licenses/by-nc-sa/4.0/or sending a letter to Creative Commons, 444 Castro Street, Suite 900, Mountain View, California, 94041, USA.