http://ece.ut.ac.ir/Classpages/F89/ECE359/HWs/HW9.pdf

http://www.engr.mun.ca/~egill/index_files/unit438212005.pdf

http://www.stanford.edu/~boyd/ee102/freq.pdf

http://cnx.org/content/m21475/latest/

http://fourier.eng.hmc.edu/e84/lectures/ch3/node1.html

http://www.ee.iitb.ac.in/~sequel/ee101/ee101_phasors_1.pdf

http://nptel.iitm.ac.in/courses/Webcourse-contents/IIT-KANPUR/esc102/node16.html

http://web.cecs.pdx.edu/~prasads/Phasors.pdf

http://www.digilentinc.com/classroom/realanalog/text/Chapter_2p7p2.pdf

http://www.ece.mtu.edu/faculty/goel/EE-2110/Prob-10.pdf

http://www.csee.wvu.edu/~schoder/ee221/EE221_Chpt10_ExamplesSol.pdf

http://www2.engr.arizona.edu/~mwm/classes/220/Homework/Homework_Assignments/Edition_8_Problems/Chapter_9_Problems.pdf

http://www.bookvc.com/Library/Book/31826/fa-IR