For a number of years the dairy section of the Iowa Agricultural Experiment Station has devoted considerable effort to an investigation of starters. This has seemed advisable because good starters have been shown to be very helpful in improving the quality of butter, which is the important dairy product of the state.
Hammer, B. W. and Baker, M. P.
"Studies on starters,"
Research Bulletin (Iowa Agriculture and Home Economics Experiment Station): Vol. 8
, Article 1.
Available at: https://lib.dr.iastate.edu/researchbulletin/vol8/iss106/1