1.
Astronomy With Your Personal Computer
by Duffett-Smith, Peter J.
ISBN: 9780521389952
List Price: $38.99
2.
Practical Astronomy With Your Calculator
by Duffett-Smith, Peter J.
ISBN: 9780521356992
List Price: $45.00
3.
Astronomy with Your Personal Computer
by Duffett-Smith, Peter J.
ISBN: 9780521321440
List Price: $40.00