"Chapbooks can loosely be defined as the small, unbound, paper-covered books that were carried and sold by itinerant peddlers known as 'chapmen.' They were in circulation from the sixteenth century until the early nineteenth...Although the chapbook has been defined rather narrowly at different times throughout history...the term has come to broadly represent a body of work that spans four centuries as well as several distinct and seemingly dissonant literary genres." From, McGill Library.
To find other examples of chapbooks, browse the library catalog by subject for Chapbooks. Also, try searching subject poetry AND keyword collection. Or try searching in subject for American poetry, or any other nationality or country, as well as time period.
When you click on the record, look at length of the book as well as make sure it's not a poet's entire collected/selected work.