What type of source is a speech?

What type of source is a Magazine?

What type of source is a Textbook?

What type of source is a photograph or picture?

What type of source is a Diary?

Which among the following are Tertiary Sources?

It is a basic type of speech that provides interesting and useful information to audience.

Which of the following are the other sources of information?

What other source of information can be useful if an issue is too complex for one person to handle, or if the audience needs to be exposed to various viewpoints at the same session?