Ricci-Parallelizable Spaces in the NS-NS Sector: AdS_3 x S^7
  We provide a class of nondilatonic solutions to the NS-NS sector of string theory. The solutions consist of products of Ricci-parallelizable spaces with adjusted radii. A representative of this class, AdS_3 x S^7, is presented in detail. Some comments on possible brane connections are made. 
Leopoldo A. Pando Zayas