Evalution of image quality in a cassegrain-type telescope with an oscillating secondary mirror [NASA TM X-3137] 
 / Erickson, E.F. 
 .- Washington, D.C.: National Areonautics and Space Administration,  1975 
 .- 24p.. 
.- ( National Areonautics and Space Administration (NASA)0   
<br/><u>Subject Headings:</u> <br/>Telescope;
<br/><U>Author Added Entry: </u><br/>Matthews, S;
<br><U>Copy Details:</u><br> Acc. No.: <b>TR002744</b>, Full Call No.: ,   Item type:  Technical Report , Location: COMPACT STORAGE (BASEMENT), <br><b>------------------------- --------------------- ------ --------- ------- ------- --------- -------- </b><br>