This book is a standard reference work for vocal literature. It lists thousands of songs, along with information about their character and range, and who publishes them.
Music for the Voice is still in copyright in the US, and not something I can offer here. However, the Internet Archive has apparently been given permission to host a digital copy on their site.
Information Page: Music for the Voice by Sergius Kagen
It is being hosted in the relatively obscure djvu format, but there is free reader software available for most major platforms.
