function claimEthers(uint256 _period) onlyReg returns (bool) {
        require(periods.length > _period);
		
        uint256 _tokensValue = sellTokens[msg.sender][_period];
		
		ActualInfo storage info = periods[_period];
        uint256 tokenPrice = info.price;
        uint256 amount = (_tokensValue.mul(tokenPrice)).div(1 ether);
        gcf.burn(_tokensValue);
        msg.sender.transfer(amount);
				
        sellTokens[msg.sender][_period] = 0;
		
		ClaimEthersEvent(msg.sender, _period, _tokensValue, tokenPrice, amount);
        
        return true;
    }