Praktische Blätter für Pflanzenschutz

1.1898 Cornell-USA* = Google (1-5), Minnesota-USA* = Google (1-5), Wisconsin-USA* = Google (1-5)
2.1899 Cornell-USA* = Google (1-5), Minnesota-USA* = Google (1-5), Wisconsin-USA* = Google (1-5)
3.1900 Cornell-USA* = Google (1-5), Minnesota-USA* = Google (1-5), Wisconsin-USA* = Google (1-5)
4.1901 Cornell-USA* = Google (1-5), Minnesota-USA* = Google (1-5), Wisconsin-USA* = Google (1-5)
5.1902 Cornell-USA* = Google (1-5), Minnesota-USA* = Google (1-5), Wisconsin-USA* = Google (1-5)