Abstract: First and second pairs of arms are respectively disposed at opposite ends of a support structure. A constrainable member (e.g., a spring) is supported at its opposite ends by corresponding ones of the arms in the pairs. This is the only constrainable member in the page clamping device. When the spring is unconstrained, the arms in each pair are normally closed. The arms in each pair are pivotable independently of the arms in the other pair. The arms in each pair have at first positions camming peripheries which cause one of such arms to pivot when the other of such arms is pivoted. The arms in each pair have at second positions camming peripheries which provide a stable relationship between the arms when the arms are in an open position. The arms in each pair are disposed on the opposite sides of a book from the arms in the other pair. With the arms in the open relationship, the pages can be easily turned.