Sabigan, Norwell A.  <br/><br/>
Design, construction and evaluation of hand tractor-drawn-ride-on leveler 
Norwell A. Sabigan  
 -  2008 
 - xiv, 56 leaves   28 cm.  
<br/><br/> Thesis (BS Agricultural Engineering) -- Mariano Marcos State University-College of Agriculture & Forestry, Batac City  
<br/><br/>Bibliography: leaves 34-35