https://doi.org/10.1351/goldbook.F02485

For a mononuclear binary complex, if a central atom (central group) M (the 'metal') and a ligand L have been defined, then in the following expressions Kn is the stepwise formation constant, and β n is the cumulative formation constant for the complex ML_{n}. They can both be referred to as stability constants (stepwise and cumulative). \[K_{n}=K(\text{ML}_{n- 1}+\text{L}\rightleftharpoons \text{ML}_{n})\] \[\beta_{n} = K(\text{M}+n\text{L}\rightleftharpoons \text{ML}_{n})\]*Source: *

Orange Book, 2^{nd} ed., p. 11 (https://media.iupac.org/publications/analytical_compendium/)

Orange Book, 2