-#all: $(patsubst %.tex,%.pdf,$(wildcard *.tex))
-all: project_description.pdf references.pdf
-pdf: all
+all: $(patsubst %.tex,%.pdf,$(wildcard *.tex))
+
+# use the following section for Rnw/knitr documents
+# all: $(patsubst %.Rnw,%.pdf,$(wildcard *.Rnw))
+# %.tex: %.Rnw
+# Rscript -e "library(knitr); knit('$<')"