for our project we want send the dynamic data to google sheets or doc. Is it possible without using any gsm-shield because we want to use sim900A....
Bit confused about what you want since SIM900A IS a GSM shield.
If you search "arduino SIM900A" you will find many examples
There is a library at http://www.gsmlib.org/ although I've not personally used it.
The SIM900A is just the chip http://www.ebay.co.uk/itm/SIM900A-Dual-band-GSM-GPRS-Wireless-Transmission-Module-Phone-Arduino-/281634425140. The OP could be referring to a bare chip, one mounted on a development board or, as you say, a shield.