http://en.wikipedia.org/wiki/LTI_system_theory

http://158.132.21.81/class/EIE312/LS102_LTIS.pdf

http://web.eecs.umich.edu/~aey/eecs206/lectures/lti2.pdf

http://itee.uq.edu.au/~coms3100/Lecture%20Notes/lec04.pdf

http://www.google.com/url?sa=t&rct=j&q=lti+systems+and+their+properties&source=web&cd=12&cad=rja&ved=0CDUQFjABOAo&url=http%3A%2F%2Fsignal.ece.utexas.edu%2F~arslan%2Fcourses%2Fdsp%2Flecture4.ppt&ei=atvmUL2oHqWA0AXRmYGwAw&usg=AFQjCNHHsgstKrkB94icuGPdz62DRDSQYA&bvm=bv.1355534169,d.d2k

http://melodi.ee.washington.edu/courses/ee518/notes/lec2.pdf

http://tintoretto.ucsd.edu/jorge/teaching/mae143a/lectures/3timedomainanalysis.pdf

http://www.cis.hut.fi/Opinnot/T-61.140/Luennot/Ch2.pdf

http://faemino.ucsd.edu/~soniamartinez/teaching/143a_SignalsSystems/data/impulse-response.pdf

http://www.csie.nctu.edu.tw/~cmliu/Courses/audio/zfreqmap.pdf

http://course.ee.ust.hk/elec215/lecture/Chapter-5-Transient-and-Frequency-responses-of-LTI-systems.pdf

http://seit.unsw.adfa.edu.au/staff/sites/valu/TEACHING/SS/lect10-Ztransform.pdf

http://people.eecs.ku.edu/~esp/class/common360/