PROGNOSIS OF MECHANICAL STABILITY OF STRUCTURAL PARTICLEBOARDS BASED ON MODIFIED PHENOL-FORMALDEHYDE RESINS DURING LONG-LASTING STAY IN THE OPEN IN REAL CLIMATIC CONDITIONS. (2026). Innovation in Woodworking Industry and Engineering Design, 4(2). http://innojs.ltu.bg/index.php/scjournal-inno/article/view/138