which BAPI to use

I'm new to suing the BAPIS and need to retrieve data from the below fields. Please guide me o which BAPI to use.

1) QALS - ZEILE/LICHN/KTEXTMAT

2) MSEG-ERFMG

3) MCH1- HSDAT/VFDAT/QNDAT

4) MKPF-XBLNR

Thanks in advance and appreciate a quick response.