@book{10887,
	author = {Hulst , H C van de },
	title = {Space research II : proceedings of the second International Space Science Symposium, Florence, April 10-14 1961, organized by the Committee on Space Research - COSPAR and Consiglio nazionale delle ricerche /},
	publisher = {North-Holland,},
	year = {1961.},
	address = {Amsterdam :  }
}