TY  - GEN
AU  - Hinnah,Dennis
AU  - Hamak,John
TI  - Survey of natural helium occurrences
T2  - U. S. Geological Survey Professional paper, 1570
KW  - Gaz hélium
KW  - Histoire
KW  - Hélium
KW  - Gaz
KW  - Etats Unis
N1  - bibliogr. p. 707
ER  -