antique vintage Bobbsey Twins books green covers hard to find old titles

Lot of eighteen very old Bobbsey Twins books - Solve a Mystery, Wonderful Secret, At Cedar Camp, At Cherry Corners, At the Circus, In the Land of Cotton, Treasure Hunting, At Spruce Lake, At Windmill Cottage, At Meadow Brook, In Eskimo Land, Keeping House, On a Houseboat, At Snow Lodge, In a Great City, On Blueberry Island, In Washington, At Mysterious Mansion.

All are loved and worn with time yellowed pages - and some old penciled marks and inscriptions. I love those old green covers!