Adams P.W. (1997): Soil and Water Conservation. An Introduction for Woodland Owners. Cornvallis, Oregon State University: 4. Baumgras J.E., Hassler C.C., Ledoux C.B. (1983): Estimating and validating harvesting system production through computer simulation. Forest Products Journal, 43: 65–71. Behjou F.K., Majnounian B., Namiranian M., Dvořák J. (2008): Time study and skidding capacity of the wheeled skidder Timberjack 450C in Caspian forests. Journal of Forest Science, 54: 183–188.Gheorghe Ignea, Stelian Alexandru Borz, Bogdan Popa (2014): Assessing timber skidding efficiency in a group shelterwood system applied to a fir-beech stand. African Journal of Agricultural Research, 9, 160-167  https://doi.org/10.5897/AJAR2013.7537 Lotfalian M. (1996): Investigation of Effect of TAF Skidder on Soil Compaction. [MSc Thesis.] Nour, Iran, Tarbiat Modares University: 114. Lotfalian M., Moafi M., Sotoudeh Foumani B., Akbari R.A. (2011): Time study and skidding capacity of the wheeled skidder Timberjack 450C. Journal of Soil Science and Environmental Management, 2: 120–124.Makineci Ender, Demir Murat, Yilmaz Ersel (2007): Long-term harvesting effects on skid road in a fir (Abies bornmulleriana Mattf.) plantation forest. Building and Environment, 42, 1538-1543  https://doi.org/10.1016/j.buildenv.2006.01.003 Matthews D.M. (1942): Cost Control in the Logging Industry. New York, London, McGraw-Hill Book Company, Inc.: 374. Naeij Nouri E. (2004): Importance of skid trails networking and determination of landing position in forest management plans. In: Regional Seminar of Forest, Rangelands, Industry with Looking to Future, Mazandaran, Iran, March 8, 2004. (in Persian) Naghdi R., Raafat Nia N., Sobhani H., Hosseini M., Jalali G.H. (2004): Investigation of production and cost of wheeled skidder Timberjack 450C in Shafaroud watershed, Iran. Iranian Journal of Natural Resources, 57: 675–687. (in Persian) Najafi A. (2007): Time study and skidding capacity of the HSM 904 skidder in Mazandaran wood and paper forest management plans. Iranian Journal of Natural Resources, 60: 921–930. (in Persian) Ozturk T. (2014): Productivity and cost of rubber – wheel-tyred tractor in a northern pine plantation forest of Turkey. Baltic Forestry, 20: 272–276. Pentek T., Nevečerel H., Poršinsky T., Pičman D., Lepoglavec K., Potočnik I. (2008): Methodology for development of secondary forest traffic infrastructure cadastre. Croatian Journal of Forest Engineering, 9: 75–83. Raafat Nia N. (2004): Investigation of effective factors on design the most appropriate patterns of skid trails. [Research Project.] Sari, Research and Development Unit in the Mazandaran Wood and Paper Industry Company: 76. Rafiei A.A., Lotfalian M., Hosseini S.A., Parsakhoo A. (2009): Determining the optimum road density for ground skidding system in Dalak Kheyl forest – Hyrcanian zone. World Applied Sciences Journal, 7: 263–270. Sarikhani N. (2008): Forest Utilization. 3rd Ed. Tehran, Iran, Tehran University Press: 728. (in Persian)Shishiuchi M. (): Optimal Skid Trail Spacing for Small Vehicles in Thinning. Journal of Forest Engineering, 5, 29-34  https://doi.org/10.1080/08435243.1993.10702652 Sobhani H. (1998): Investigation of necessity of using cable logging systems. Iranian Journal of Natural Resources, 51: 87–97. (in Persian)Søvde Nils Egil, Løkketangen Arne, Talbot Bruce (2013): Applicability of the GRASP metaheuristic method in designing machine trail layout. Forest Science and Technology, 9, 187-194  https://doi.org/10.1080/21580103.2013.839279 Zecic Z., Krapan A.P.B., Vuksuic S. (2005): Productivity of C Holder 870 F tractor with double drum winch Igland 4002 in thinning beech stands. Croatian Journal of Forest Engineering, 27: 49–56. Zobeiri M. (2005): Forest Inventory. 3rd Ed. Tehran, Iran, Tehran University Press: 401. (in Persian)