CK-12 Physical Science - For Middle School

9.5. References http://www.ck12.org

25. Christopher Auyeung. CK-12 Foundation. CC BY-NC 3.0


26. Blue lake: Courtesy of NASA Earth Observatory; Algae pond: Dwight Burdette; Pitcher plant: Geoff
    Gallice (Flickr:ggalice). Blue lake: http://commons.wikimedia.org/wiki/File:Harmful_Bloom_in_Lake_Atit
    l%C3%A1n,_Guatemala.jpg; Algae pond: http://commons.wikimedia.org/wiki/File:Algae_Covered_Pond_C
    herry_Hill_Road_Superior_Township_Michigan.JPG; Pitcher plant: http://www.flickr.com/photos/11014423
    @N07/2916359254. Blue lake: Public Domain; Algae pond: CC BY 3.0; Pitcher plant: CC BY 2.0


27. Top: Flickr:LearningLark; Bottom: Laura Guerin (CK-12 Foundation). Top: http://www.flickr.com/photos/44
    282411@N04/7610164322/. Top: CC BY 2.0; Bottom: CC BY-NC 3.0