Rapp, R. R. <br/><br/>
Cloud-free line-of-sight calculations / 
R. R. Rapp, C. Schutz 
 - California :  Rand Corporation,  1972 
 - iii, 25 pages ;  28 cm. 
 - The Rand paper series ;  p. 4883 .
 - Rand paper series ;  p. 4883 .
<br/><br/>Bibliography: p. 24-25.