British English vs American English

https://www.hicom-asia.com/british-vs-american-english-for-business/

https://www.youtube.com/watch?v=2nAnT3PASak

https://www.engvid.com/american-english-british-english-8-grammar-differences/

https://www.verbling.com/articles/post/eight-differences-between-british-and-am

https://www.englishclub.com/vocabulary/british-american.htm

http://www.oxforddictionaries.com/words/british-and-american-terms

http://www.englisch-hilfen.de/en/words/be-ae.htm

https://learnenglish.britishcouncil.org/grammar/intermediate-to-upper-intermediate/british-english-and-american-english
http://www.englisch-hilfen.de/en/exercises/languages/be_ae.htm

http://www.english-in-chester.co.uk/e-learning/lesson/differences-between-british-english-and-american-english/