Walraven, P. L.; Lebeek, H. J. Foveal Sensitivity of the Human Eye in the Near Infrared. J. Opt. Soc. Am. 1963, 53 (6): 765–766. PMID 13998626. doi:10.1364/josa.53.000765.
"there was, to our knowledge, no actual, direct estimate of numbers of cells or of neurons in the entire human brain to be cited until 2009. A reasonable approximation was provided by Williams and Herrup (1988), from the compilation of partial numbers in the literature. These authors estimated the number of neurons in the human brain at about 85 billion [...] With more recent estimates of 21–26 billion neurons in the cerebral cortex (Pelvig et al., 2008 ) and 101 billion neurons in the cerebellum (Andersen et al., 1992 ), however, the total number of neurons in the human brain would increase to over 120 billion neurons." Herculano-Houzel, Suzana. The human brain in numbers: a linearly scaled-up primate brain. Front. Hum. Neurosci. 2009, 3: 31. PMC 2776484. PMID 19915731. doi:10.3389/neuro.09.031.2009.
Kapitsa, Sergei P. The phenomenological theory of world population growth. Physics-Uspekhi. 1996, 39 (1): 57–71. Bibcode:1996PhyU...39...57K. S2CID 250877833. doi:10.1070/pu1996v039n01abeh000127. (citing the range of 80 to 150 billion, citing K. M. Weiss, Human Biology 56637, 1984, and N. Keyfitz, Applied Mathematical Demography, New York: Wiley, 1977). C. Haub, "How Many People Have Ever Lived on Earth?", Population Today 23.2), pp. 5–6, cited an estimate of 105 billion births since 50,000 BC, updated to 107 billion as of 2011 in Haub, Carl. How Many People Have Ever Lived on Earth?. Population Reference Bureau. October 2011 [April 29, 2013]. (原始内容存档于April 24, 2013). (due to the high infant mortality in pre-modern times, close to half of this number would not have lived past infancy).
Kapitsa, Sergei P. The phenomenological theory of world population growth. Physics-Uspekhi. 1996, 39 (1): 57–71. Bibcode:1996PhyU...39...57K. S2CID 250877833. doi:10.1070/pu1996v039n01abeh000127. (citing the range of 80 to 150 billion, citing K. M. Weiss, Human Biology 56637, 1984, and N. Keyfitz, Applied Mathematical Demography, New York: Wiley, 1977). C. Haub, "How Many People Have Ever Lived on Earth?", Population Today 23.2), pp. 5–6, cited an estimate of 105 billion births since 50,000 BC, updated to 107 billion as of 2011 in Haub, Carl. How Many People Have Ever Lived on Earth?. Population Reference Bureau. October 2011 [April 29, 2013]. (原始内容存档于April 24, 2013). (due to the high infant mortality in pre-modern times, close to half of this number would not have lived past infancy).
Walraven, P. L.; Lebeek, H. J. Foveal Sensitivity of the Human Eye in the Near Infrared. J. Opt. Soc. Am. 1963, 53 (6): 765–766. PMID 13998626. doi:10.1364/josa.53.000765.
"there was, to our knowledge, no actual, direct estimate of numbers of cells or of neurons in the entire human brain to be cited until 2009. A reasonable approximation was provided by Williams and Herrup (1988), from the compilation of partial numbers in the literature. These authors estimated the number of neurons in the human brain at about 85 billion [...] With more recent estimates of 21–26 billion neurons in the cerebral cortex (Pelvig et al., 2008 ) and 101 billion neurons in the cerebellum (Andersen et al., 1992 ), however, the total number of neurons in the human brain would increase to over 120 billion neurons." Herculano-Houzel, Suzana. The human brain in numbers: a linearly scaled-up primate brain. Front. Hum. Neurosci. 2009, 3: 31. PMC 2776484. PMID 19915731. doi:10.3389/neuro.09.031.2009.
Kapitsa, Sergei P. The phenomenological theory of world population growth. Physics-Uspekhi. 1996, 39 (1): 57–71. Bibcode:1996PhyU...39...57K. S2CID 250877833. doi:10.1070/pu1996v039n01abeh000127. (citing the range of 80 to 150 billion, citing K. M. Weiss, Human Biology 56637, 1984, and N. Keyfitz, Applied Mathematical Demography, New York: Wiley, 1977). C. Haub, "How Many People Have Ever Lived on Earth?", Population Today 23.2), pp. 5–6, cited an estimate of 105 billion births since 50,000 BC, updated to 107 billion as of 2011 in Haub, Carl. How Many People Have Ever Lived on Earth?. Population Reference Bureau. October 2011 [April 29, 2013]. (原始内容存档于April 24, 2013). (due to the high infant mortality in pre-modern times, close to half of this number would not have lived past infancy).
Kapitsa, Sergei P. The phenomenological theory of world population growth. Physics-Uspekhi. 1996, 39 (1): 57–71. Bibcode:1996PhyU...39...57K. S2CID 250877833. doi:10.1070/pu1996v039n01abeh000127. (citing the range of 80 to 150 billion, citing K. M. Weiss, Human Biology 56637, 1984, and N. Keyfitz, Applied Mathematical Demography, New York: Wiley, 1977). C. Haub, "How Many People Have Ever Lived on Earth?", Population Today 23.2), pp. 5–6, cited an estimate of 105 billion births since 50,000 BC, updated to 107 billion as of 2011 in Haub, Carl. How Many People Have Ever Lived on Earth?. Population Reference Bureau. October 2011 [April 29, 2013]. (原始内容存档于April 24, 2013). (due to the high infant mortality in pre-modern times, close to half of this number would not have lived past infancy).
Kapitsa, Sergei P. The phenomenological theory of world population growth. Physics-Uspekhi. 1996, 39 (1): 57–71. Bibcode:1996PhyU...39...57K. S2CID 250877833. doi:10.1070/pu1996v039n01abeh000127. (citing the range of 80 to 150 billion, citing K. M. Weiss, Human Biology 56637, 1984, and N. Keyfitz, Applied Mathematical Demography, New York: Wiley, 1977). C. Haub, "How Many People Have Ever Lived on Earth?", Population Today 23.2), pp. 5–6, cited an estimate of 105 billion births since 50,000 BC, updated to 107 billion as of 2011 in Haub, Carl. How Many People Have Ever Lived on Earth?. Population Reference Bureau. October 2011 [April 29, 2013]. (原始内容存档于April 24, 2013). (due to the high infant mortality in pre-modern times, close to half of this number would not have lived past infancy).