"Estrontium" on poster I was looking at a poster for an international chemistry olympiad. Its background contains some random elements as periodic table tiles. 

One of them said "Estrontium." A google search returned nothing but clip art. 
Is this an accepted spelling internationally (similar to the way Spanish speakers prefix "e" on words starting with "s" followed by a consonant) or a careless typo on their part? My chemistry teacher was equally confused.
"Estrontium" is not used as an element name in any language. It appears that the error traces to a single user by the name of Alejo Miranda (listed as from Ecuador) who has posted a large collection of periodic tables and individual element clip art to shuttersock, iphoto, etc. in which "estrontium" is incorrectly used as the English name for strontium.  The Spanish periodic table correctly uses estroncio.  The link to the gllery at shutterstock is 

https://www.shutterstock.com/g/Alejo+Miranda?searchterm=estrontium&amp;search_source=base_gallery&amp;language=en&amp;sort=popular&amp;measurement=px&amp;safe=true