On EUR-Lex, locate the 'Treaty establishing the European Economic Community (1957)' within the founding treaties. Once found, identify its unique CELEX number. Then, access its official document information page to find and state the 'Date of document', 'Date of effect', and 'Date of signature'.
Navigate to the EUR-Lex homepage. Access the 'Founding treaties' section. Locate the 'Treaty establishing the European Economic Community (1957)' in the list. Identify and extract its CELEX number. Navigate to the document's dedicated page using the CELEX number. Go to the 'Document information' section on the dedicated page. Extract and state the 'Date of document', 'Date of effect', and 'Date of signature' from the 'Dates' section.
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 via the CELEX number link. 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'.