DISTANCES AND DISTRIBUTION OF PLANETARY NEBULAE

[11] CAHN JH, 1968, 34 IAU S, P44

[12] CANNON AJ, 1926, 837 HARV B

[13] CLARKE W, 1965, THESIS U CALIFORNIA

[14] OBSERVATIONS OF PLANETARY NEBULAE AT 3 MICROWAVE FREQUENCIES [J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1967, 135 (02) : 139 - &

[15] FLEMING M, 1911, 167 HARV CIRC

[16] FLEMING M, 1910, 138 HARV CIRC

[17] FRANCMAN L, 1962, ASTRON ZH, V39, P256

[18] LOCAL INTERSTELLAR REDDENING [J]. ASTROPHYSICAL JOURNAL, 1969, 157 (2P1) : 611 - &

[19] GURZADYAN GA, 1969, PLANETARY NEBULAE

[20] HARO G, 1962, B OBS TONANTZINTAL T, V3, P37

[11] CAHN JH, 1968, 34 IAU S, P44

[12] CANNON AJ, 1926, 837 HARV B

[13] CLARKE W, 1965, THESIS U CALIFORNIA

[14] OBSERVATIONS OF PLANETARY NEBULAE AT 3 MICROWAVE FREQUENCIES [J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1967, 135 (02) : 139 - &

[15] FLEMING M, 1911, 167 HARV CIRC

[16] FLEMING M, 1910, 138 HARV CIRC

[17] FRANCMAN L, 1962, ASTRON ZH, V39, P256

[18] LOCAL INTERSTELLAR REDDENING [J]. ASTROPHYSICAL JOURNAL, 1969, 157 (2P1) : 611 - &

[19] GURZADYAN GA, 1969, PLANETARY NEBULAE

[20] HARO G, 1962, B OBS TONANTZINTAL T, V3, P37