You may wish to have a reference to a paper or collection of papers presented at a conference or seminar. These are generally known as conference papers or proceedings.
These are the details you will need to construct a reference for a conference paper, the punctuation marks at the end of each element being those you should use to put the reference together.
For example
Anderson JC. Current Status of Chorion Villus Biopsy. In: Tudenhope D, Chenoweth J, editors. Proceedings of the Fourth Congress of the Australian Perinatal Society; 1986 Sept. 3-6; Brisbane, Queensland: Australian Perinatal Society; 1987. p. 190-6.