Importance of Supersuperexchange Interactions in Determining the Dimensionality of Magnetic Properties. Determination of Strongly Interacting Spin Exchange Paths in A
2
Cu(PO
4
)
2
(A = Ba, Sr), ACuP
2
O
7
(Ba, Ca, Sr, Pb), CaCuGe
2
O
6
, and Cu
2
UO
2
(PO
4
)
2
on the Basis of Qualitative Spin Dimer Analysis