NIOS D.EL.ED COURSE 509 COMPLETE SHORT NOTES e-Book (in Hindi) This e-Book contains short notes along with exam oriented important Questions for NIOS D.EL.ED Course- 509 उच्च प्राथमिक स्तर पर सामाजिक विज्ञान का अधिगम. Once you complete payment successfully, you will get email with e-Book download option at given Email-Id, You will also receive confirmation message on mobile at given mobile number.