Transaction log backup - Only full recovery model? I am reading this book from Microsoft - it says:
"A log backup cannot be performed unless the database is in full recovery model and an initial full backup has been performed"

Is this correct? I know simple recovery model doesn't support transaction log backup. But think I have read somewhere that full and also bulk recovery model supports transaction log backup.
No, this is not correct.

See SQL Server Recovery Models

If you are utilising the BULK recovery model, this will function the same as the FULL recovery model apart from specific minimally logged operations (SELECT INTO, BULK INSERT, CREATE INDEX...)

If you do not set up log backups, you risk your log files filling.