structure.step

big_tree http://upload.wikimedia.org/wikipedia/commons/thumb/3/3b/CalaverasBigTrees1.jpg/512px-CalaverasBigTrees1.jpg

stork http://upload.wikimedia.org/wikipedia/commons/thumb/c/c6/Stork_%28Palic%2C_Serbia%29.jpg/512px-Stork_%28Palic%2C_Serbia%29.jpg

larches http://upload.wikimedia.org/wikipedia/commons/thumb/8/8c/Creek_and_old-growth_forest-Larch_Mountain.jpg/512px-Creek_and_old-growth_forest-Larch_Mountain.jpg

# sa2000 http://www.financialtransparency.org/wp-content/uploads/2010/08/South-Africa-2000.jpg

salmon http://s0.geograph.org.uk/geophotos/03/19/18/3191883_da59af55.jpg

bifurcation http://dushoff.github.io/notebook/git_push/logistic.Rout.png

israelpop https://upload.wikimedia.org/wikipedia/commons/8/80/Pyramide_Israel.PNG

cypruspop https://upload.wikimedia.org/wikipedia/commons/c/c4/Pyramide_Chypre.PNG

iranpop https://upload.wikimedia.org/wikipedia/commons/thumb/f/f9/Iran-age-pyramid.svg/1000px-Iran-age-pyramid.svg.png

canadapop https://upload.wikimedia.org/wikipedia/commons/4/49/Pyramideca2010.jpg

bahrainpop https://upload.wikimedia.org/wikipedia/commons/7/72/Bahrain_population_pyramid_2012.jpg

cambodiapop https://upload.wikimedia.org/wikipedia/commons/9/95/Pyramide_Cambodge.PNG