For the benefit of the new readers, we repeate the instructions (although they can be found in many of the earlier postings).
Instructions for one sweater:
Need about 80 grams of yarn, the needles size 3,5 or 4.
Cast on 70 stitches and knit 2 two purl and 2 knit stitches for 22 cm. Then knit 4 cm so that the 22 stitches in the middle continue as before (2/2) but 24 stitches on both sides are knitted only knit stitches ( no purl). Then make the square hole in the middle by terminating the 22 stitches in the centre and continuing both sides separately for 6 cm. Then re-cast on the centre and continue again 4 cm by 2/2 with 22 in the centre and 24 on both sides as knit only. Then make all 2/2 and knit 22 cm more before terminating. It is in the end one long piece (about 58 cm) with the square hole in the centre. Fold it and stitch the sides and leave the openings for the sleeves.