Tomlin, K. <br/><br/>
Low cost monitoring for freshwaters :  field techniques / 
K. Tomlin and D. V. Chapman. 
 - London :  GEMS Monitoring and Assessement Research Centre, University of London,  1989. 
 - 44 p. :  ill. ;  30 cm. 
<br/><br/>Includes bibliographical references. 
<br/><br/> Open access. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Freshwater ecology.