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Priority to NL6506558ApriorityCriticalpatent/NL6506558A/xx
Publication of NL6506558ApublicationCriticalpatent/NL6506558A/xx
G09B—EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS
G09B3/00—Manually or mechanically operated teaching appliances working with questions and answers
G09B3/02—Manually or mechanically operated teaching appliances working with questions and answers of the type wherein the student is expected to construct an answer to the question which is presented or wherein the machine gives an answer to the question presented by a student
G09B3/04—Manually or mechanically operated teaching appliances working with questions and answers of the type wherein the student is expected to construct an answer to the question which is presented or wherein the machine gives an answer to the question presented by a student of chart form
B—PERFORMING OPERATIONS; TRANSPORTING
B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS