Presidential republics with an executive presidency separate from the legislature
Semi-presidential system with both an executive presidency and a separate head of government that leads the rest of the executive, who is appointed by the president and accountable to the legislature
Parliamentary republics with a ceremonial and non-executive president, where a separate head of government leads the executive and is dependent on the confidence of the legislature
Republics in which a combined head of state and government is elected by, or nominated by, the legislature and may or may not be subject to parliamentary confidence
Clark, William Roberts; Golder, Matt; Golder, Sona Nadenichek (23 March 2012). Principles of Comparative Politics (ඉංග්රීසි බසින්). SAGE. ISBN 9781608716791.