Defeat in parliament (Robertson): Beginning of Jennings's period in office; Robertson 'Resigned after defeat in Legislative Assembly on censure motion', see Clune and Turner, vol. 1 table 3, pp. 228-229 (see 'Sources', below). Jennings was then commissioned to form a government.
Resignation of premier (Jennings): Jennings 'Resigned although still possessing a majority in Legislative Assembly', see Clune and Turner, vol. 1 table 3, pp. 228-229 (see 'Sources', below).
References: For a description and analysis of the style of parliamentary government in this period, see David Clune and Ken Turner, 'Introduction: The Colonial Premiers', pp. 1-12, in Clune and Turner vol. 1 (see, 'Sources', below), and Peter Loveday and A W Martin, Parliament, Factions and Parties: The First Thirty Years of Responsible Government in New South Wales, 1856-1889, (Melbourne: Melbourne University Press, 1966).
For a survey of Jennings's political career, see T W Campbell, 'Sir Patrick Alfred Jennings', in Clune and Turner, vol. 1, pp. 181-188 (see 'Sources', below), and A E Cahill, 'Jennings, Sir Patrick Alfred (1831-1897)', in Douglas Pike (general editor), Australian Dictionary of Biography, vol. 4, pp. 154-155, (Melbourne: Melbourne University Press, 1972, ISBN 0522840345).
David Clune and Ken Turner (editors), The Premiers of New South Wales, vol. 1, (1856-1901), (Sydney: Federation Press, 2006, ISBN 186287550); G N Hawker, The Parliament of New South Wales 1856-1965, appendix C, (Ultimo, NSW: Government Printer, 1971); New South Wales, Parliament, The New South Wales Parliamentary Record: Legislative Council and Legislative Assembly, 1824-1999, vol. VI, pp. 246-308, (Sydney: Parliament of New South Wales, 1999). In consulting these sources, note the difference between ministries and periods in office.