Detective boys of masangkay:  and closed-door mystery/ 
Bernalyn Hapin Sastrillo. 
 - Quezon City:  Adarna House,  2018. 
 - 154p. 
<br/><br/><label>ISBN: </label>9789715087360 
<br/><br/><label>Dewey Class. No.: </label>FIC/FIL Sa799 2018