Trade payables and other liabilities include: trade payables, accrued expenses and deferred income, pension obligations and current tax as well as other interest-bearing and non-interest-bearing liabilities.           Valuation principles of financial assets and liabilities:   Investments are classified into two groups, namely financial assets held for trading purposes and financial assets held-to-maturity. The purpose of assets held for trading is to produce a gain in the short term and they are presented as part of current investments. Held-to-maturity investments are intended to be held until the maturity date and they are reported as part of non-current investments. On the closing date all the Group's investments are in the category held for trading purposes. Investments held for trading purposes are value at fair value using the market prices on the closing date and the present value of cash flows method. Unrealised and realised gains and losses arising from changes in the fair value of investments are recognised in the income statement's financial income and expenses.   All financial liabilities are valued at allocated acquisition cost or fair value cost through profit and loss using the effective interest method.   All derivatives are classified as held for trading purposes and are valued at fair value. The most important valuation principles of derivatives are described in note 28 Financial risks.   The fair value of other financial assets and liabilities is assumed to correspond approximately to their carrying amount due to their short maturity or because their fair values cannot be reliably determined.