Sahama, Th. G <br/><br/>
Mineralogy and Petrology of Lava Flow from Mt. Nyiradgongo, Belgian Congo 

 - Helsinki :   Suomalainen Tiedeakatemia,   1953. 
 - 25 p. ;   18 cm. 
 - Annales Academiae Scientiarum Fennicae. Serie A. III. Geologica-Geographica ;   35 .
<br/><br/> Contiene además: Parallel growth of nepheline and microperthitic kalsite from North Kivu, Balgian Congo.