Thuli's mattress / 
illustrated by Marjorien van Heerden  and written by Elizabeth Littlewort et al. 
 - Cambridge :  Cambridge University press,  c 1996. 
 - 16 p. :  ill. 
<br/><br/><label>ISBN: </label>0521578639 9780521578639 
<br/><br/><label>Dewey Class. No.: </label>823.914