Helping Children Cope with everyday or traumatic situations is usually judged a humane task; Mastering Stress Through Books and Stories is a more debatable proposition, sometimes referred to as ""bibliotherapy;"" using books as emotional catalysts. For years, only Martha Wolfenstein's 1940s study, using a book written to order by Leo Rosten, was available to give credence to the theory; Fassler, a psychologist at Yale's Child Study Center, comes up with more recent and extensive research studies, several involving her own Behavioral Publications books, to add weight to the argument. Anyone who has seen a young child open up to a good book can acknowledge the plausibility of the theory, and Fassler is familiar with the best on children's library shelves (for ages 4-8)--the classics of Brown, Zolotow, Krauss, Minarik, and Steig among others. For the most part, she recommends appropriate titles for each situation (death, illness and hospitalization, adoption, divorce, etc.) and also indicates imperfections such as heavy-handedness, distracting illustrations, or pointless sexual stereotypes. And her professional sources are impeccable, which should insure a strong reception from social service workers itching for these annotated referrals. Resistance to uninspired books of noble purpose and to the idea of pushing them on children will, of course, continue, but Fassler's position is less likely to be faulted because most of the books she includes have intrinsic merits and because she is looking only to open up communication, not to engineer a particular emotional experience. Less single-minded and more knowledgeable than, say, Bettelheim on fairy tales, and attuned to the finer cadences of children's responses.