Quite numerous services. Few of those that you can book online
or via phone are.
Transtar: http://www.transtar.com.sg/olcoachquery.php
Five Stars Tour: 6294 7011
Konsortium:
http://www.konsortium.com.sg/coach_tickets/gent_tics.php
Grassland Express: Tel: 6292 1166
I prefer the top 2 for their 1st class buses that have personal tv,
large and reclinable (and some with messaging features) seats,
although they charge a slightly higher premium for these
