What we saw at Madame World's fair ...
a series of letters from the twins at the Panama-Pacific international exposition to their cousins at home.
APA Citation
Gordon, E., Levinson, S. (1915). What we saw at Madame World's fair ..: a series of letters from the twins at the Panama-Pacific international exposition to their cousins at home. San Francisco: Levinson.
MLA Citation
Gordon, Elizabeth, 1866-1922, and Samuel Levinson. What We Saw At Madame World's Fair ..: a Series of Letters From the Twins At the Panama-Pacific International Exposition to Their Cousins At Home. San Francisco: Levinson, 1915.
Warning: These citations may not always be complete (especially for serials).