My copy of Mees has over 1100 pages and is a standard book size (about 7x9 in) but very thick. Mees and James is a larger book in length and width, about 9x11 and thus has fewer pages.

In the Mees reference above and in Haist, they show plots of activity and potassium salts are 4x slower than sodium salts in fixation. Calcium also appears to slow rates.

Haist gives the actual reference to additional work, and there are published patents on how to overcome the deleterious effects of potassium ion on fix rate.

AFAIK, potassium salts have no significant effect on development, but do have an effect on emulsion precipitation.

PE