B. Petersen

Pollination of Thlaspi alpestre by Selfing and by Insects in the Alpine Zone of Colorado

B. Petersen, 1977 .

FREEZE-TOLERANCE IN THE SUBARCTIC EARTHWORM EISENIA NORDENSKIOELDI (EISEN)

M. Holmstrup, B. Petersen, 1997 .

Some novelties in presumed males of Leptanillinae (Hym., Formicidae).

Norm Johnson, Joe Cora, B. Petersen, 1968 .