(Percentage depletion deductions) may be related to crude oil.
A deduction may be determined under a (cost depletion method).
A (percentage depletion deduction) may pertain-to a corporation.
(Percentage depletion deductions) may constitute an item of (tax preference).
An excess of a (percentage depletion deduction) may be viewed as a (tax expenditure).
(Percentage depletion) may be computed without regard to a basis.
A (cost depletion method) may permit (cost recovery deductions).
A (research effort) may focus on effects of (oxygen depletion).
Effects can be constituted-of-or-filled-with (oxygen depletion).
Chemical reactions can be responsible for an (ozone depletion).