@BOOK{NAP12349, title = "On the Balance of Shuttle and ELV Launches: Letter Report", doi = "10.17226/12349", url = "https://nap.nationalacademies.org/catalog/12349/on-the-balance-of-shuttle-and-elv-launches-letter-report", year = 1986, publisher = "The National Academies Press", address = "Washington, DC" }