Laws of Cricket 1947 Code (Second Edition) - Law 24
A bowler shall finish an "Over" in progress unless he be incapacitated or be suspended for unfair play. He shall be allowed to change ends as often as desired, provided only that he shall not bowl two "Overs" consecutively in one innings. A Bowler may require the Batsman at the wicket from which he is bowling to stand on whichever side of it he may direct.
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