Catalog › gamma-Decalactone + gamma-Undecalactone
These two appear together in 3 of the accords published to the PerfuMate community. That is a record of two materials used together in real formulations, and it is only that: a record of use, not a recommendation engine. The accords are listed below so the evidence can be read.
Both are filed under Fruity, Gourmand, Aldehydic. Within their families they share the peach, apricot, coconut, waxy sub-categories.
Each accord is a formula published to the PerfuMate community, and these are PerfuMate's own reference accords rather than third-party work. The figures are each material's share of the concentrate in that accord.