PSHELL Formulation for Multiple MIDs

Can you please help me understand how the MID1, MID2, MID3 and MID4 entries on a PSHELL card work together to represent the complete ABD matrix of a laminate? I was reading the documentation, which states that only G13 and G23 are needed for the MID4 entry. If this is the case, how is the extension-bending coupling represented?

Thank you,

-Justin