ea. vol: 47p. illus. photogs. glossary. index. (Mystery of Series). CIP. Crestwood House. 1987. PLB $10.95. Gr 4-6 These books present an accept able blend of old and new information. The format appears aimed at younger readers; older readers could be insulted by the style. The tone is flatly informa tive, neither sensational nor conde scending, with ample use of complex words in short sentences. Of the four, The Bermuda Triangle and Bigfoot seem to be the most well-documented. Although a fairly reasonable balance is struck in the text between truth, the ory, quotations, and conjecture, the il lustrations tend to be significantly mis leading. They are abundant, but not particularly good or distinguished in any way. Colors are typically dark and murky. Some illustrations are poorly captioned; some show hypothetical places or entities but are presented as factual. Illustrations are sometimes poorly juxtaposed with the text. Too bad the final quality of these books does not match the fair and even-hand ed research. Leslie Chamberlin, Napa City-County Library, Calif.