Since "Reflections" is a very common title for music collections, the most useful and relevant result for your search is "Reflections," a collection of original piano solos by the composer Dennis Alexander.
Below is the information you are most likely looking for, regarding the sheet music book.
Digital annotation tools (like Adobe Acrobat or GoodNotes) let readers highlight passages and write margin notes without defacing a physical book.
When searching for the "PDF," it is important to identify which book the piece originates from. "Reflections" appears in several Dennis Alexander compilations, the most notable being:
Note on Similar Works: Dennis Alexander has a specific piece simply titled "Reflections," but he also has a very famous collection called "24 Character Preludes." Within that collection, each piece corresponds to a different key and mood. Users searching for the PDF should verify if they want the specific piece titled "Reflections" or the "Character Preludes" collection.