21. Number 33 - The Ribbed Pine-Borer: Memoir Collection: Core Historical Literature of Agriculture Publisher: Cornell University, Agricultural Experiment Station Publication Place: Ithaca, N.Y. Date: 1920 Format: Issue
22. Number 34 - An Economic Study of Farm Layout: Memoir Collection: Core Historical Literature of Agriculture Publisher: Cornell University, Agricultural Experiment Station Publication Place: Ithaca, N.Y. Date: 1920 Format: Issue
23. Number 35 - Some Effects of Potassium Salts on Soils: Memoir Collection: Core Historical Literature of Agriculture Publisher: Cornell University, Agricultural Experiment Station Publication Place: Ithaca, N.Y. Date: 1920 Format: Issue
24. Number 36 - Resistance of the Roots of Some Fruit Species to Low Temperature: Memoir Collection: Core Historical Literature of Agriculture Publisher: Cornell University, Agricultural Experiment Station Publication Place: Ithaca, N.Y. Date: 1920 Format: Issue
25. Number 37 - A Modified Babcock Method for Determining Fat in Butter: Memoir Collection: Core Historical Literature of Agriculture Publisher: Cornell University, Agricultural Experiment Station Publication Place: Ithaca, N.Y. Date: 1920 Format: Issue
26. Number 38 - The Crane-Flies of New York. Part II. Biology and Phylogeny: Memoir Collection: Core Historical Literature of Agriculture Publisher: Cornell University, Agricultural Experiment Station Publication Place: Ithaca, N.Y. Date: 1920 Format: Issue
27. Number 471: Bulletin Collection: Core Historical Literature of Agriculture Publisher: New York State Agricultural Experiment Station Publication Place: Geneva, N.Y. Date: 1920 Format: Issue
28. Number 472: Bulletin Collection: Core Historical Literature of Agriculture Publisher: New York State Agricultural Experiment Station Publication Place: Geneva, N.Y. Date: 1920 Format: Issue
29. Number 472, Edition popular: Bulletin Collection: Core Historical Literature of Agriculture Publisher: New York State Agricultural Experiment Station Publication Place: Geneva, N.Y. Date: 1920 Format: Issue
30. Number 473: Bulletin Collection: Core Historical Literature of Agriculture Publisher: New York State Agricultural Experiment Station Publication Place: Geneva, N.Y. Date: 1920 Format: Issue