@misc{12094, author = {Bj{\o}rn Nielsen and Aslak Tveito}, title = {A Weighted Output Least Squares Approach to Upscaling of One-Phase Flow in Heterogeneous Reservoirs}, year = {1997}, journal = {Presented at Fourth SIAM Conference on Mathematical and Computational Issues in the Geosciences in New Mexico, USA}, month = {June}, }