On EUR-Lex, locate the 'Treaty establishing the European Economic Community (1957)' within the 'Founding treaties' section. Once found, identify its CELEX number. Then, access the document's information page and list the 'Date of document', 'Date of effect', and 'Date of signature'.
Navigate to the EUR-Lex homepage. Navigate to the 'Founding treaties' section under 'EU law' -> 'Treaties'. Locate the 'Treaty establishing the European Economic Community (1957)' in the list. Identify and extract its CELEX number. Click the CELEX number link for the 'Treaty establishing the European Economic Community (1957)' to access its dedicated page. On the document's page, click on the 'Document information' link. On the 'Document information' page, locate the 'Dates' section. Extract and state all dates listed within the 'Dates' section (Date of document, Date of effect, Date of signature).
Successfully navigate to the 'Founding treaties' page. Identify the CELEX number for the 'Treaty establishing the European Economic Community (1957)' as '11957E/TXT'. Successfully access the document's dedicated page. Successfully navigate to the 'Document information' section. State the 'Date of document' as '25/03/1957'. State the 'Date of effect' as '01/01/1958'. State the 'Date of signature' as '25/03/1957'.