To give credit to a photographer, we suggest including "via Twenty20 / photographer's Twenty20 username" and hyperlinking the photographer's gallery. Another option is to use "Photo Credit: Twenty20".
How do I find the photographer's username? The photographer's Twenty20 username (or "gallery name") is how they are displayed to users of Twenty20 and other sources who view their work: twenty20.com/username.
Here are some examples: