The preliminary bibliography
lists each source that looks as if it might be in speech
should be prepared after the speaker has finished researching the speech
identifies sources that the speaker is sure will be used in the speech
should contain a maximum of three or four sources

Lists each source that looks as if it might be helpful in speech

Explanation:

The preliminary bibliography is the list of each relevant research source in relation to the theme of the speech, from single publications, newsletters, journals, magazines, books, researches, monographs, theses, etc. to oral communication: radio, tape recording magnetic or audiovisual: films and television. Its purpose is to put the researcher in direct contact with everything that was written or produced and is related to the theme of the speech.

ich statement best shows a problem in travels with charley?

one sharp difficulty presented itself. in the intervening twenty-five years my name had become reasonably well known.

this being so, my trip demanded that i leave my name and my identity at home.

i had to go alone and i had to be self-contained, a kind of casual turtle carrying his house on his back.

with all this in mind i wrote to the head office of a great corporation which manufactures trucks.