Browne, Nuclear Data Sheets 93, 802, National Nuclear Data Center (NNDC), Evaluated Nuclear Structure Data File (ENSDF
), http://www.nndc.bnl.gov/ (2001).
To account for this peak all the isotopes in ENSDF
database  have been analyzed and few candidates (with the correct spectral shape and an ancestor live time greater than 30 days) have been identified.
The half-lives, gamma-ray emission probabilities, and uncertainties used for the detector efficiency calibrations are those listed in the Evaluation Nuclear Structure Data File (ENSDF
) tables available from the National Nuclear Data Center (12) or from the Laboratorie National Henri Becquerel (13).