Yoann & Vehlmann took over the official Spirou series in 2008. Their first album, Alerte aux zorkons (Spirou #51, “Zorkons Alert”), came out in 2010. During that time, Yoann had to experiment a bit to adapt his style to the more traditional look readers expected, and in illustrations and short stories running up to the album, you can see it evolving rapidly (much like the zorkons themselves). This unused opening to the album, for example, shows clear differences from the look of the final version.
It was included in the limited edition of Alerte aux zorkons published by Khani Editions. The last image is not from the comic, but a loose ex libris (bookplate print) that came with the book. Because of the size, the pages have been merged from multiple scans, and this may have introduced some artifacts and seams. I’m reelly sörry!
And just for the fun of it, I’d like to point out this detail from the first page:
Edit: Pages 2 and 3 have been updated in order to fix a translation error and to improve the lettering (6/9/2015).