When citing an online lecture, use the following basic format: Author Last Name, First Initial(s). (Year). Title of lecture: Subtitles if applicable [file format]. Retrieved from URL.
For example: Cain, S. (2012). The power of introverts [video file]. Retrieved from http://www.ted.com/talks/susan_cain_the_power_of_introverts?language=en.
You can also use this format to cite notes or materials from a lecture that are found online. For example: Slingsby, S. (2013). RE Revision Notes [PowerPoint slides]. Retrieved from http://getrevising.co.uk/resources/re_powerpoint_for_unit_8.
Whenever you directly reference a lecture source in the body of your paper, include an in-text citation noting the source of the information. This should include the author of the lecture and the year. For example: (Cain, 2012) or (Slingsby, 2013).