I collect pictures for my captions from a great variety of sites. Usually they remain quite a time on my hard drive before I eventually use and publish them. As by that time in most of the cases I have forgotten from where I retrieved them, I am unable to do what good internet publishing practice would demand and mention the picture's source. I am sorry for that! So, if anyone discoveres a picture of which he/she has copyright, please let me know and I mention its source or, if requested, remove the picture from my site. Thank you!
Some sites where I recently retrieved pictures from are listed on the side-bar: picture sources.