[41] Ripley (1900) 165–179.
[42] Thus Burkitt (1921) 1. 42, 127, but Macalister (1921) 1. 373, 376, 582, states that the steppe conditions had passed before the beginning of the Solutrean period.
[43] Burkitt (1921) 1. 130–133.
[44] Burkitt (1921) 1. 132, 135.
[45] Burkitt (1921) 1. 129; Macalister (1921) 1. 434.
[46] Burkitt (1921) 1. 129.
[47] Montelius (1921).
[48] Nordmann (1922).
[49] Burkitt (1921) 1. 232.
[50] Fleure (1920) 21–25.