Directive 86/609
http://www.ecbr.eu/pdf/86-609-eec_en.pdf

Ets123
http://conventions.coe.int/treaty/en/treaties/html/123.htm

Euroguide
http://www.rsmpress.co.uk/bkfelasa.htm

FELASA recommendations
http://www.felasa.eu/document-library/cat_view/17-guidelines-a-recommendations