Croll, J. G. A. <br/><br/>
Force systems and equilibrium 

 -  Chatto and Windus  1974 
 - 96p.  ill.  21cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Force systems
<br/><br/><label>LC Class. No.: </label>PAM QC73.C92