firstgrade-all.pdf: firstgrade-cover.pdf firstgrade-toc.pdf firstgrade-body.pdf pdfconcat $@ $^ firstgrade-cover.pdf: firstgrade.pdf pdfselect 37 37 $< $@ firstgrade-toc.pdf: firstgrade.pdf pdfselect 36 36 $< $@ firstgrade-body.pdf: firstgrade.pdf pdfselect 1 35 $< $@