As for a free PDF download, I can suggest a few options:

You're looking for information about "Dekada '70" by Lualhati Bautista and possibly a free PDF download.

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If you are looking for or the full text

Finding the Voice of a Generation: A Deep Dive into Lualhati Bautista’s Dekada '70

If you are researching the book for school or personal interest, BOOK REVIEW: Dekada '70 - - Hawaii Filipino Chronicle