Nicolas, Marie Rose A.  <br/><br/>
Determination of lead at Padsan river, Laoag City  
Marie Rose A. Nicolas 
 -  2004 
 - xv, 46 leaves   28 cm.  
<br/><br/> Thesis (BS Environmental Science) -- Mariano Marcos State University-College of Agriculture, Food & Sustainable Development,Batac City  
<br/><br/>Bibliography: leaf 21