1st EditionKlaus Theopold, Paul Flowers, Richard Langley, William R. Robinson1,783 explanations
11th EditionDarrell Ebbing, Steven D. Gammon2,796 explanations
3rd EditionMartin S. Silberberg2,048 explanations
2nd EditionKlaus Theopold, Paul Flowers, Richard Langley, William R. Robinson1,716 explanations