Subject
- Latex1
- Lathes1
- Lead arsenate1
- Lime1
- Limekilns1
- Limestone1
- Limestone industry1
- Lyness, Helen1
- Machine parts--Inspection1
- McFadden, Marion1
- McIntire, Otis Ray, 1918-19961
- Michigan--Pere Marquette River1
- Mikols, Stan1
- Mines and mineral resources1
- Moe, Clyde1
- Monroe, Roger1
- Morrison, Hugh1
- Motion picture projectors1
- Myers, Wilbur1
- Nystrom, Lois1