1. Takeru Higuchi: A memorial tribute,1991
2. Mainz VV,Girolami GS.Chemical Genealogy Database. (〈http://www.scs.uiuc.edu/∼mainzv/Web_Genealogy/〉). (This site is very extensively referenced.)
3. The Catholic Encyclopedia has a web site at (〈www.newadvent.org/cathen/05189a.htm〉).
4. The Galileo project maintains an extensive web site and multiple links (〈http://es.rice.edu/ES/humsoc/Galileo/〉).
5. R. A. Hatch maintains a very good web site at (〈http://web.clas.ufl.edu/users/rhatch/〉).