Answer:
Letters and publications written by Nazi leaders before the Second World War.
Explanation:
This answer is correct because this historian is searching for the motives of these perpetrators, letters and publications can tell their thoughts and conversations.
The Sanderson' behavior was UNETHICAL AND ILLEGAL; THEIR ACTION CONSTITUTE THEFT FROM THE AIRLINES.
Their action is unethical because it is not in line with the ethical behavior that is expected of a person that is holding a position like the one Jane Sanderson held. The behavior is illegal because it constitutes stealing, which is a punishable offence under the constitution of the country.
