M. Sponheimer, T. F. Robinson, T. E. Cerling, L. Tegland, B. L. Roeder, L. Ayliffe, M. D. Dearing, J. R. Ehleringer,
Turnover of stable carbon isotopes in the muscle, liver, and breath CO2 of alpacas (Lama pacos). Rapid Communications in Mass Spectrometry. ,vol. 20, pp. 1395- 1399 ,(2006) ,
10.1002/RCM.2454