His most famous is What is to Be Done.

Pamphlets is the plural for pamphlet.

You have to specify which people and which pamphlet.

To write a bibliography entry for a pamphlet, include the author's name, the title of the pamphlet in italics, the publication date, the publisher, and the format (e.g., pamphlet). For example: Author Last Name, First Name. Title of Pamphlet. Publication Year. Publisher. Pamphlet.

it depends on what kind of pamphlet or brochure it is.