Data: United States, ethnicGroup, African Americans; United States, leaderTitle, President of the United States; A Wizard of Mars, country, United States

A Wizard of Mars originates from the United States, where the title of the leader is the President and where African Americans are an ethnic group.

Data: Amsterdam Airport Schiphol, cityServed, Amsterdam; Amsterdam, leader, Eberhard van der Laan

Amsterdam Airport Schiphol serves the city of Amsterdam whose leader is Eberhard van der Laan.

Data: Apollo 8, commander, Frank Borman
Frank Borman was the Apollo 8 commander.