http://www2.warwick.ac.uk/fac/soc/philosophy/people/miller/foreword2009.pdf
http://strangebeautiful.com/other-texts/popper-logic-scientific-discovery.pdf
The first pdf is a useful commentary on Popper's "Objective Knowledge" from
David Miller, Popper's former Research Assistant and a foremost exponent of
Popper's theory of knowledge.
The second is a copy of Popper's _LdF_ of "Logik der Forschung" ['Logic of
Research"] in its English translation as "The Logic of Scientific Discovery".
Happy St. Patrick's Day to all.
DL