. . "Mercury (Planet)" . . . . . "Mercury" . "Mercury"@en . . . . . . . . "Electronic books" . . "\"Describes what is known about Mercury from the photographs taken by Project Mariner.\"--Title page verso." . . "Juvenile works" . "Juvenile works"@en . . . . . . . . "Describes what is known about Mercury from the photographs taken by Project Mariner." . . "Describes what is known about Mercury from the photographs taken by Project Mariner."@en . "Mercury (Planet)" . . "Project Mariner (U.S.)" . . "Project Mariner." . .