Interestingly SF Gateway has added the following note to all four books:
"Authorised by the estate of the Gothic master John Bellairs."
Ah, but there’s an added bonus in all this. The publisher is also releasing an electronic version of The Face in the Frost, featuring this oft-seen gem-of-a-quote from author Ursula K. LeGuin:
"Authentic fantasy by a writer who knows what wizardry is all about."
With these five titles it now appears that both North American and European markets each have the 13 Bellairs/Strickland titles available for readers. Enjoy!