NHibernate - Mapping a String Foreign Key

Teams (
 TeamId INT PRIMARY KEY,
 Name VARCHAR(30)
)

Players (
 PlayerId INT PRIMARY KEY,
 Team VARCHAR(30)
)

<bag name="Players">
    <key column="Team" foreign-key="Name" />
    <one-to-many class="DataTransfer.Player, DataTransfer" />
</bag>

<bag name="Players">
   <key column="Team" property-ref="Team" />
   <one-to-many class="Player" property-ref="Team" />
</bag>

<many-to-one name="Players" class="DataTransfer.Player, DataTransfer"
             column="Name" property-ref="Team" />