Historical forex market data have the following columns or prices:

askopen, askclose, askhigh,asklow, bidopen ,bidclose,bidlow, bidhigh.my question is which of these fields/prices are normally used to calculate the technical indicators such as Bollinger Bands,Moving Averages, RSI, Oscillator etc.i made many findings but getting conflicting information about which of the prices to use.I reaaly need a help on this matter.Thanks in advance.