If the author has not officially released a PDF, then any "Misa Delgado Book 1 PDF" you find is likely unverified and unauthorized.
Your best course of action is simple:
is a verified compilation of Filipino liturgical music composed by Lester Delgado . Launched in 2007, this first volume was inspired by a desire to create music specifically for Catholic liturgical celebrations. Key Details and Contents misa delgado book 1 pdf verified