Henry George (1912). “Progress and Poverty: An Inquiry Into the Cause of Industrial Depressions and of Increase of Want with Increase of Wealth; the Remedy”
Henry George (1916). “Progress and Poverty: An Inquiry Into the Cause of Industrial Depressions and of Increase of Want with Increase of Wealth; the Remedy”
Henry George (2014). “A Perplexed Philosopher: Being an Examination of Mr. Herbert Spencer's Various Utterances on the Land Question, with Some Incidental Reference to His Synthetic Philosophy”, p.6, epubli