Cramer, Z., Spear, J., & Eichbaum, W. (1810). Cramer's Pittsburgh magazine almanack extra, for the year of our Lord 1811.: ... Calculated for the meridian of Pittsburgh, in lat. 40° 38' west, but will serve without any sensible variation for the states of Ohio, Virginia, Kentucky, &c. Pittsburgh,: Printed and published by Cramer, Spear & Eichbaum, at the Franklin Head Book-store, in Market Street, between Front and Second Streets ....

Cramer, Zadok, John Spear, and William Eichbaum. Cramer's Pittsburgh Magazine Almanack Extra, for the Year of Our Lord 1811.: ... Calculated for the Meridian of Pittsburgh, in Lat. 40° 38' West, but Will Serve Without Any Sensible Variation for the States of Ohio, Virginia, Kentucky, &c. Pittsburgh,: Printed and published by Cramer, Spear & Eichbaum, at the Franklin Head Book-store, in Market Street, between Front and Second Streets ..., 1810.

Cramer, Zadok, John Spear, and William Eichbaum. Cramer's Pittsburgh Magazine Almanack Extra, for the Year of Our Lord 1811.: ... Calculated for the Meridian of Pittsburgh, in Lat. 40° 38' West, but Will Serve Without Any Sensible Variation for the States of Ohio, Virginia, Kentucky, &c. Pittsburgh,: Printed and published by Cramer, Spear & Eichbaum, at the Franklin Head Book-store, in Market Street, between Front and Second Streets ..., 1810.