<!ELEMENT list (type,publisher,contacts,periods)>
	<!ELEMENT type (#PCDATA)>
		<!ATTLIST type version CDATA #REQUIRED>
	<!ELEMENT publisher (publisher-name,url)>
		<!ATTLIST publisher publisher-id CDATA #REQUIRED>
		<!ELEMENT publisher-name (#PCDATA)>
		<!ELEMENT url (#PCDATA)>
	<!ELEMENT contacts (email+)>
		<!ELEMENT email (email-name,address)>
			<!ELEMENT email-name (#PCDATA)>
			<!ELEMENT address (#PCDATA)>
	<!ELEMENT periods (period+)>
		<!ELEMENT period (newsletter+)>
			<!ATTLIST period type CDATA #REQUIRED>
			<!ATTLIST period number CDATA #REQUIRED>
			<!ATTLIST period year CDATA #REQUIRED>
			<!ELEMENT newsletter (#PCDATA)>
				<!ATTLIST newsletter newsletter-id CDATA #REQUIRED>