Clarkson, T. (1789). An essay on the comparative efficiency of regulation or abolition: As applied to the slave trade : shewing that the latter only can remove the evils to be found in that commerce. London: Printed by James Phillips.

Clarkson, Thomas. An Essay On the Comparative Efficiency of Regulation or Abolition: As Applied to the Slave Trade : Shewing That the Latter Only Can Remove the Evils to Be Found in That Commerce. London: Printed by James Phillips, 1789.

Clarkson, Thomas. An Essay On the Comparative Efficiency of Regulation or Abolition: As Applied to the Slave Trade : Shewing That the Latter Only Can Remove the Evils to Be Found in That Commerce. London: Printed by James Phillips, 1789.