* {{cite book | last=Campbell-Kelly | first=Martin | title=ICL | publisher=Oxford University Press, USA | publication-place=Oxford : New York | date=1989 | isbn=0-19-853918-5}}
<ref name="o100">{{cite book | last=Campbell-Kelly | first=Martin | title=ICL | publisher=Oxford University Press, USA | publication-place=Oxford : New York | date=1989 | isbn=0-19-853918-5 | page=}}</ref>