https://dds.las.ac.cn/service/document?appId=a1vacbnPuv9qJRzJvdNXfsesj9JbIa6e&appKey=sPBA4vANLzjnW1k5eufEcc4k7dxfNraW&ts=1763013199022&signature=4e4d91fd066d1925561e05884400e3de&articleTitle=Birth+and+Evolution+of+Massive+Stars+and+Stellar+Groups&articleAuthor=Wilfried+Boland%2C+Hugo+van+Woerden&publicationTitle=Birth+and+Evolution+of+Massive+Stars+and+Stellar+Groups&language=&publicationType=1&publishYear=1985&isn=9789027721358&publisher=Springer+Netherlands