http://feeds.feedburner.com/PrimaryResources
http://soerya.surabaya.go.id/AuP/e-DU.KONTEN/edukasi.net/Fisika/Animasi.Fisika/
http://www.notesandsketches.co.uk/Index.html
http://www.harphys.com/
http://www.indi-smart.com/
http://bptikp-jateng.net/data/mpi/mpi/fisika/