Locker, John & Kenneth F. Klopfenstein books & textbook
Numerical Trigonometry
Locker, John & Kenneth F. Klopfenstein
The Davies Group, Publishers /2002T Paperback
Analytic Trigonometry
John Locker Kenneth F. Klopfenstein
Daviesgroup Publishers /2001T Paperback / 144 Pages
isbn-10: 1888570245 / isbn-13: 9781888570243