Ten results, no labels, and five weights to reconstruct.

Five boxes, ten weighings

Strategist
Numerical territory

Riddle statement

Five boxes have unknown weights.

Every possible pair was weighed exactly once. The note recording which two boxes produced each result was then lost, but these ten weights, in kilograms, were preserved:

20, 26, 32, 33, 39, 42, 45, 48, 54, and 61

Can you determine with certainty how much each box weighs?