Borela, Eugenio Jr. V., <br/><br/>
Telephone cable tone detector/ 
Eugenio V. Borela Jr., Vincent E. Malapo, Ervin F. Tagum 
 - Nabua, Camarines Sur :  Camarines sur Polytechnic Colleges ;  2005. 
 - 58 leaves. 
<br/><br/>Undergraduate Thesis (BSECE) - Electronics Engineering