Symbols and Codes - code without the space after the "&" and don't forget the ";" as shown

Symbol   - Code
φ      - & phi;
Φ      - & Phi;

ψ     - & psi;
Ψ     - & Psi;

ρ     - & rho;
Ρ     - & Rho;

π      - & pi;
Π      - & Pi;

Γ   - & Gamma;
γ   - & gamma;

χ     - & chi;

κ   - & kappa;

λ  - & lambda;
Λ - & Lambda;

θ   - & theta;
Θ   - & Theta;

τ     - & tau;

Μ      - & Mu;
μ      - & mu;

Ω   - & Omega;
ω   - & omega;

∫     - & int;
∇   - & nabla;

α   - & alpha;
Α   - & Alpha;

β    - & beta;
Β    - & Beta;

δ   - & delta;
Δ   - & Delta;

ε - & epsilon;

υ - & upsilon;

ν      - & nu;
Ν      - & Nu;

σ   - & sigma;
Σ   - & Sigma;

ζ    - & zeta;
η     - & eta;

∂    - & part;
≈   - & asymp;
≡   - & equiv;
±  - & plusmn;
√   - & radic;