Chapter XIII. Ratio and Proportion.
Algebra Part 1, GDML_Books, (1889), p. 255 / Harvested from
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@article{PPN585262896+DMDLOG_0017,
     title = {Chapter XIII. Ratio and Proportion.},
     booktitle = {Algebra Part 1},
     series = {GDML\_Books},
     publisher = {Black},
     address = {Edinburgh},
     year = {1889},
     pages = {255},
     url = {http://dml.mathdoc.fr/item/PPN585262896+DMDLOG_0017}
}

 (éd.). Chapter XIII. Ratio and Proportion., dans Algebra Part 1, GDML_Books,  (1889), p. 255. http://gdmltest.u-ga.fr/item/PPN585262896+DMDLOG_0017/