@article {634,
	title = {A Photographic Periodogram of the Sun-Spot Numbers},
	journal = {The Astrophysical Journal, },
	volume = {XL },
	year = {1914},
	keywords = {Douglass, numbers, periodogram, photo, photographic, spot, sun, sun spot},
	author = {Douglass, A.E.}
}
@article {629,
	title = {A Cloud-Like Spot on the Terminator of Mars},
	year = {1895},
	keywords = {Douglass, mars, spot},
	author = {Douglass, A.E.}
}
