TY  - JOUR
AU  - Yamashita, Shinji
TI  - Derivatives and Length-Preserving Maps
JO  - Canadian mathematical bulletin
PY  - 1987
SP  - 379
EP  - 384
VL  - 30
IS  - 3
UR  - http://geodesic.mathdoc.fr/articles/10.4153/CMB-1987-056-x/
DO  - 10.4153/CMB-1987-056-x
ID  - 10_4153_CMB_1987_056_x
ER  -