Step 1: Identify which oxyacids can contain \(P-P\) bonds.
Oxyacids having more than one phosphorus atom may have \(P-P\) linkage.
Step 2: Analyze options.
- \(H_3PO_4\), \(H_3PO_3\), \(H_3PO_2\) contain single P \(\Rightarrow\) no \(P-P\) bond.
- \(H_4P_2O_7\) has \(P-O-P\) linkage, not \(P-P\).
- \(H_3P_2O_6\) is hypophosphoric acid and contains \(P-P\) bond.
Step 3: Correct pair.
So pair containing \(P-P\) bond is:
\[
H_3PO_3 \text{ and } H_3P_2O_6
\]
Final Answer:
\[
\boxed{H_3PO_3,\;H_3P_2O_6}
\]