All content, unless otherwise stated, is available under a Creative Commons Attribution License (CC-BY 4.0). Users have the right to copy or redistribute materials and to build upon the material for any purpose, even commercially.

The following conditions apply:

• Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.

• No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.