Percival, A. S. (1925). PRESCRIBING SPECTACLES (2): ALTERATION OF THE POWER OF A CYLINDER WHEN USED FOR CLOSE WORK.
Παραπομπή Chicago StylePercival, A. S. PRESCRIBING SPECTACLES (2): ALTERATION OF THE POWER OF A CYLINDER WHEN USED FOR CLOSE WORK. 1925.
Παραπομπή MLAPercival, A. S. PRESCRIBING SPECTACLES (2): ALTERATION OF THE POWER OF A CYLINDER WHEN USED FOR CLOSE WORK. 1925.
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