Alaska constitution
Article II: the legislature
Section 16

Upon receipt of a veto message during a regular session of the legislature, the legislature shall meet immediately in joint session and reconsider passage of the vetoed bill or item. Bills to raise revenue and appropriation bills or items, although vetoed, become law by affirmative vote of three-fourths of the membership of the legislature. Other vetoed bills become law by affirmative vote of two-thirds of the membership of the legislature. Bills vetoed after adjournment of the first regular session of the legislature shall be reconsidered by the legislature sitting as one body no later than the fifth day of the next regular or special session of that legislature. Bills vetoed after adjournment of the second regular session shall be reconsidered by the legislature sitting as one body no later than the fifth day of a special session of that legislature, if one is called. The vote on reconsideration of a vetoed bill shall be entered on the journals of both houses.