Some notes on the Ulam stability of the general linear equation

Ulam stability of functional equations in 2-Banach spaces via the fixed point method

“…A lot of information about the Cauchy and Jensen equations as well as their applications and stability can be found in [1,[35][36][37], whereas some very recent stability outcomes on Eq. (6) were published for instance in [2,42] (see also [3], where the stability of yet another special case of (6) was considered in 2-Banach spaces).…”