* {{cite book | last=Olby | first=Robert Cecil | title=Companion to the History of Modern Science | publisher=Routledge | publication-place=London ; New York | date=1990 | isbn=0-415-01988-5}}
<ref name="i122">{{cite book | last=Olby | first=Robert Cecil | title=Companion to the History of Modern Science | publisher=Routledge | publication-place=London ; New York | date=1990 | isbn=0-415-01988-5 | page=}}</ref>