Editing Concretion (section)

== External links ==
{{Commons category|Concretions}}
* Dietrich, R.V., 2002, [https://web.archive.org/web/20081202111650/http://www.cst.cmich.edu/users/dietr1rv/concretions/index.htm ''Carbonate Concretions – A Bibliography''], The Wayback Machine. and [http://condor.cmich.edu/cdm/singleitem/collection/p1610-01coll1/id/3165/rec/4228 PDF file of ''Carbonate Concretions – A Bibliography''] {{Webarchive|url=https://web.archive.org/web/20141217052538/http://condor.cmich.edu/cdm/singleitem/collection/p1610-01coll1/id/3165/rec/4228 |date=2014-12-17 }}, CMU Online Digital Object Repository, [[Central Michigan University]], Mount Pleasant, Michigan.
* Biek, B., 2002, [https://www.dmr.nd.gov/ndgs/ndnotes/concretions/concretions.asp ''Concretions and Nodules in North Dakota''] North Dakota Geological Survey, Bismarck, North Dakota.
* Everhart, M., 2004, [http://www.oceansofkansas.com/FieldGuide5.html ''A Field Guide to Fossils of the Smoky Hill ChalkPart 5: Coprolites, Pearls, Fossilized Wood and other Remains''] Part of the [http://www.oceansofkansas.com Oceans of Kansas] web site.
* Hansen, M.C., 1994, [https://web.archive.org/web/20081216220206/http://www.ohiodnr.com/Portals/10/pdf/GeoFacts/geof04.pdf ''Ohio Shale Concretions'' PDF version, 270 KB] Ohio Division of Geological Survey GeoFacts n. 4, pp.&nbsp;1–2.
* Hanson, W.D., and J.M. Howard, 2005, [https://web.archive.org/web/20100527173151/http://www.geology.ar.gov/mis_pub_info/MP%2022%20Prim%20Boulders.pdf ''Spherical Boulders in North-Central Arkansas'' PDF version, 2.8 MB] Arkansas Geological Commission Miscellaneous Publication n. 22, pp.&nbsp;1–23.
* Heinrich, P.V., 2007, [http://www.hgms.org/BBG/Aug07.pdf ''The Giant Concretions of Rock City Kansas'' PDF version, 836 KB] {{Webarchive|url=https://web.archive.org/web/20161020134413/http://www.hgms.org/BBG/Aug07.pdf |date=2016-10-20 }} BackBender's Gazette. vol. 38, no. 8, pp.&nbsp;6–12.
* Hokianga Tourism Association, nd, [http://hokiangatourism.org.nz/activities/attractions/koutu-boulders ''Koutu Boulders ANY ONE FOR A GAME OF BOWLS?''] and [https://web.archive.org/web/20081014032805/http://hokianga.net.nz/hokianga/koutu/koutu_boulders.htm ''Koutu Boulders, Hokianga Harbour, Northland, New Zealand''] High-quality pictures of cannonball concretions.
* Irna, 2006, [http://irna.lautre.net/Tout-ce-que-la-nature-ne-peut-pas,45.html All that nature can never do, part IV : stone spheres] {{Webarchive|url=https://web.archive.org/web/20160303225759/http://irna.lautre.net/Tout-ce-que-la-nature-ne-peut-pas,45.html |date=2016-03-03 }}
* Irna, 2007a, [http://irna.lautre.net/Stone-balls-in-France-too.html Stone balls : in France too!] {{Webarchive|url=https://web.archive.org/web/20150713044420/http://irna.lautre.net/Stone-balls-in-France-too.html |date=2015-07-13 }}
* Irna, 2007b, [http://irna.lautre.net/Boules-de-pierre-en-Slovaquie.html Stone balls in Slovakia, Czech Republic and Poland] {{Webarchive|url=https://web.archive.org/web/20080315043453/http://irna.lautre.net/Boules-de-pierre-en-Slovaquie.html |date=2008-03-15}}
* Katz, B., 1998, [http://www.desertusa.com/mag98/oct/papr/geo_conc.html ''Concretions''] Digital West Media, Inc.
* Kuban, Glen J., 2006–2008. [http://paleo.cc/paluxy/nevada.htm Nevada Shoe Prints?]
* McCollum, A., nd, [http://allanmccollum.net/amcimages/imperialvalleyconcretions.html ''Sand Concretions from Imperial Valley''], a collection of articles maintained by an American artist.
* Mozley, P.S., [https://web.archive.org/web/20120304075635/http://allanmccollum.net/amcimages/mozley.html ''Concretions, bombs, and groundwater''], on-line version of an overview paper originally published by the New Mexico Bureau of Geology and Mineral Resources.
* United States Geological Survey, nd, [https://web.archive.org/web/20141015163848/http://nd.water.usgs.gov/lewisandclark/points/concretions.html ''Cannonball concretion'']
* University of Utah, 2004, [http://unews.utah.edu/news_releases/earth-has-039blueberries039-like-mars/ ''Earth Has 'Blueberries' Like Mars 'Moqui Marbles' Formed in Groundwater in Utah's National Parks''] {{Webarchive|url=https://web.archive.org/web/20150802011237/http://unews.utah.edu/news_releases/earth-has-039blueberries039-like-mars/ |date=2015-08-02 }} press release about iron oxide and Martian concretions
* Tessa Koumoundouros: [https://www.sciencealert.com/these-strange-bulging-geological-manifestations-loom-over-romania These Eerie 'Living Stones' in Romania Are Fantastical, And Totally Real]. On: science<sup>alert</sup>. 25 December 2020: About Trovants in [[Costești (Vâlcea)|Costești]], [[Bozioru|Ulmet]] and other locations in [[Romania]]

[[Category:Sedimentary rocks]]
[[Category:Minerals]]
[[Category:Petrology]]
[[Category:Mineralogy]]
[[Category:Pseudofossils]]
[[Category:Stones]]