Minn. Stat. § 290.20: NET INCOME; ALLOCATION TO STATE.

Subdivision 1. Statutory methods to determine; petition for use of other methods.

The methods prescribed by section 290.191 shall be presumed to determine fairly and correctly the taxpayer's taxable net income allocable to this state. If the methods prescribed by section 290.191 do not fairly reflect all or any part of taxable net income allocable to this state, the taxpayer may petition for or the commissioner may require the determination of net income by the use of another method, if that method fairly reflects net income. These other methods may include:

(1) separate accounting;

(2) excluding any one or more of the factors;

(3) including one or more additional factors; or

(4) some other method.

Subd. 1a. Petition form.

A petition within the meaning of this section must be filed by the taxpayer in the form required by the commissioner.

Subd. 2. Nonapplication of statutory methods.

The methods prescribed by subdivision 1 shall not be applicable wherever and insofar as the taxpayer's business consists of the mining, producing, smelting, refining, or any combination of these activities of copper and nickel ores.