@article{10_4153_CJM_1968_114_5,
     author = {Nagabhushanam, K. and Bhagavan, C. S. K.},
     title = {Non-Stationary {Processes} and {Spectrum}},
     journal = {Canadian journal of mathematics},
     pages = {1203--1206},
     year = {1968},
     volume = {20},
     number = {1},
     doi = {10.4153/CJM-1968-114-5},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1968-114-5/}
}