Basopo, Norah <br/><br/>
Effects of pesticides on esterase activity of two species of freshwater snails helisoma duryi and lymnaea natalensis / 
N. Basopo. 
 - Bulawayo :  Natioanl University of Science and Technology,  2007 
 - xx, 197 p.:  ill. (some col.);  28 cm. 
<br/><br/> Includes bibliographical references.  Thesis(PhD)---NUST,2007. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Pesticides.<br/>Freshwater snails<br/>Water. Aquatic biology.