What was the references for this statement? In the order of importance, the first two most important factors that play a role in the regulation of aldosterone secretion are (1) K+ion concentration in the ECF and (2) Renin-angiotensin system.

It is not possible to determine the specific references for this statement without additional information. However, the regulation of aldosterone secretion by K+ ion concentration in the extracellular fluid (ECF) and the renin-angiotensin system is a well-established concept in physiology and can be found in various textbooks and scientific articles on the subject.