@article {384, title = {A 36nW, 7 ppm/oC Fully On-Chip Clock Source System for Ultra-Low Power Applications}, journal = {Journal of Low Power Electronics and Applications (JLPEA)}, volume = {6}, year = {2016}, author = {Akella, D. and A. Shrivastava and C. Duan and B. H. Calhoun} }