Is referencing needed when using statistics or other data that is freely available from a publicly accessible website?

Is referencing needed When summarizing the cause of undisputed past events and where there is an agreement by most commentators on cause and effect?

Is referencing necessary when paraphrasing a definition found on a website and when no writer, editor or author’s name is shown?

Is referencing needed when summarizing in a concluding paragraph of your assignment what you discussed and referenced earlier in your text?

Where should the citation go in the following text?

A major study of British school leavers concluded that parents had a major influence on the kind of work entered by their children. The children were influenced over a long period of time by the values and ideas about work of their parents. A later study reached the same conclusion, and showed a link between the social and economic status of parents and the work attitudes and aspirations of their teenage children.

Is this the correct way to do referencing?

Http://www.bbc.co.uk/bob/callcentres/ [Accessed 09/08/2004].

Is referencing necessary when summarizing undisputed and commonplace facts about the world?

Is the following an acceptable form of reference?

It has been argued (Hayden White, 1978) that history is simply a special sort of fiction governed by particular rules of presentation.

A trainee submitted an assignment with only in-text citations and no list of references. Is this acceptable?