Hillman, William S. <br/><br/>
Photoperiodism in plants and animals / 
William S. Hillman. 
 - Burlington, N.C. :  Scientific Publications Division, Carolina Biological Supply Co.,  1979. 
 - 16 p. :  ill. 
 - Carolina biology readers ;  107 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Photoperiodism.