2004

Kim, E., Hopke, P. K., Larson, T. V., Covert, D. S., Analysis of Ambient Particle Size Distributions Using Unmix and Positive Matrix Factorization, ES&T, 38, 202-209, 2004. abstract
- applies PMF and UNMIX to DMPS data in Seattle in winter 2000-2001
- 4 factors: residential wood burning, likely secondary aerosol, diesel emissions, motor vehicle emissions

2005

Zhou, L., Hopke, P. K., Stanier, C. O., Pandis, S. N., Ondov, J. M., Pancras, J. P., Investigation of the relationship between chemical composition and size distribution of airborne particles by partial least squares and positive matrix factorization, JGR, 110, D07S18, 2005 abstract
- applies Partial Least Squares (PLS) and PMF to SMPS, APS, PM2.5 species, and gas phase species in Pittsburgh for 5 days in July 2001
- 11 factors: secondary nitrate I, remote traffic, secondary nitrate II, secondary sulfate, lead, diesel traffic, coal-fired power plant, steel mill, nucleation, local traffic, coke plant

Zhou, L., Kim, E., Hopke, P. K., Stanier, C. O., Pandis, S. N., Mining airborne particulate size distribution data by positive matrix factorization, JGR, 110, D07S19, 2005 abstract
- applies PMF to SMPS, APS, PM2.5 species, and gas phase species in Pittsburgh for each month (12 mo) from July 2001 to June 2002
- 5 factors: local traffic, nucleation, mixed factors representing secondary and aged primary aerosol, fresh primary aerosol from local combustion sources; stationary combustion sources; remote Pittsburgh traffic, local point sources

Larson, T. V., Covert, D. S., Kim, E., Elleman, R., Schreuder, A. B., Lumley, T., Combining size distribution and chemical species measurements into a multivariate receptor model of PM2.5, JGR, 111, D10S09, 2006 abstract
- applies ME2 to DMPS, APS, speciated data from from filters (with "missing mass" as a species" in Seattle from Feb. 2000 to June 2003
  - both mass and volume are constrained, and linked by the "average apparent particle density" with Q-terms for mass and volume
  - size distributions are downweighted by a factor of 10 to emphasize composition data
- 11 factors: vegetative burning, mobile 1, sulfate rich secondary aerosol, nitrate rich secondary aerosol, oil combustion, mobile 3, aged sea salt, airborne soil, sea salt, mobile 2, metals processing

Han, J. S., Moon, K. J., Lee, S. J., Kim, Y. J., Ryu, S. Y., Yi, S. M., Size-resolved source apportionment of ambient particles by positive matrix factorization at Gosan backgrounds site in East Asia, ACP, 6, 211-233, 2006 abstract
- applies PMF separately to 19 elements from 8 stages of DRUM sampler data in Gosan, Korea in spring 2002