ram upgrade

Hello!

I have a  Inspiron 15R (5520) laptop, processor: Intel® Core™ i7-3612QM CPU @ 2.10GHz × 8 

graphics : Intel® Ivybridge Mobile 

64 bit.

I have a RAM of 4 GB, may I upgrade it to 8 GB?, in that case, where may I find the specs of the memory in order to buy it?,

Thanks in advance,

Igor