(2) The remuneration paid by an employer located in this state for work performed in other states by an employee who works part of the time in a calendar year in this and other states shall be included in payroll when the work in the other states is covered by unemployment insurance laws. The Director of the Employment Department shall prescribe the manner of providing proof of the payment of payroll taxes on the wages of an employee earned while working in other states. [Amended by 1955 c.655 §6; 1959 c.606 §1; 1965 c.205 §1; 1971 c.463 §10; 1973 c.300 §3; 1973 c.810 §1; 1975 c.354 §1; 1983 c.508 §2; 1995 c.79 §331; 2005 c.183 §4]