Collection
- Kentucky Works Progress Administration… (7)
- North Carolina Works Progress… (5)
- Maryland Works Progress Administration… (4)
- New Hampshire Works Progress… (4)
- Mississippi Works Progress… (3)
- Tennessee Works Progress Administration… (3)
- Arkansas Works Progress Administration… (2)
- Georiga Works Progress Administration… (2)
- Indiana Works Progress Administration… (2)
- Louisiana Works Progress Administration… (2)
![Mechanization, Employment, and Output Per Man in Bituminous-Coal Mining- Vol. 1 by Willard E. Hotchkiss [et al.]](https://exploreuk.uky.edu/dips/xt79cn6xz88z/data/books_fw4_7_e_9_v1_xt79cn6xz88z/33362_ftb.jpg "Mechanization, Employment, and Output Per Man in Bituminous-Coal Mining- Vol. 1 by Willard E. Hotchkiss [et al.]")
![Mechanization, Employment, and Output Per Man in Bituminous-Coal Mining- Vol. 2 by Willard E. Hotchkiss [et al.]](https://exploreuk.uky.edu/dips/xt7zcr5nc05g/data/books_fw4_7_e_9_v2_xt7zcr5nc05g/33586_ftb.jpg "Mechanization, Employment, and Output Per Man in Bituminous-Coal Mining- Vol. 2 by Willard E. Hotchkiss [et al.]")
![Mechanization, Employment, and Output Per Man in Petroleum and Natural-Gas production by O.E. Kiessling [et al.]](https://exploreuk.uky.edu/dips/xt72z31nj52w/data/books_fw4_7_e_10_xt72z31nj52w/34683_ftb.jpg "Mechanization, Employment, and Output Per Man in Petroleum and Natural-Gas production by O.E. Kiessling [et al.]")
