All my photos are licensed under CC-BY-SA-4.0 and can be used according to this license. Wherever you use my photos you must add at least the following Copyright:
CC-BY-SA-4.0 Markus Giger (commons.wikimedia.org)
You also find this in the exif data of my photos. If you find there CC-BY-SA-2.5-CH you are also allowed to use this license. But I allow also for these photos to use the CC-BY-SA-4.0 license. For further questions you can reach me under my username, written as guerbetaler, (at) yahoo.fr.