Կաղապար:Greenwood&Earnshaw
Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0-08-037941-9. {{cite book}}: Cite has empty unknown parameter: |name-list-format= (օգնություն)
Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0-08-037941-9. {{cite book}}: Cite has empty unknown parameter: |name-list-format= (օգնություն)