A crow's foot is used to describe the "many" side of a one-to-many or many-to-many relationship, as
highlighted in Figure 7-5. A crow's foot looks quite literally like the imprint of a crow's foot in the earth, with three splayed "toes."
By now, you should get the idea that many toes implies more than one and thus many, regardless of how many toes a crow
actually has. Figure 7-5 shows a crow's foot between the AUTHOR and PUBLICATION tables, indicating a
one-to-many relationship between AUTHOR and PUBLICATION tables.